Apparatus and method for transmitting or receiving data in wireless power transmission system

ABSTRACT

The present application describes a wireless power reception device comprising: a power pickup circuit configured to receive, from a wireless power transmission device, a wireless power generated on the basis of magnetic coupling in a power transmission phase; and a communication and control circuit configured to transmit, to the wireless power transmission device, a configuration packet including first dual data stream information, or to receive, from the wireless power transmission device, a capability packet including second dual data stream information. Upper layer data can be effectively exchanged by clearly recognizing whether the upper layer data is bidirectionally transmitted between the wireless power transmission device and the wireless power reception device, and accuracy of power loss and saving of processing resources can be achieved by synchronizing the timing of calculating the power loss between the wireless power transmission device and the wireless power reception device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/995,558, filed on Aug. 17, 2020, which is a continuation pursuant to35 U.S.C. § 119(e) of International Application PCT/KR2019/014105, withan international filing date of Oct. 25, 2019, which claims the benefitof Korean Patent Application No. 10-2018-0129205 filed on Oct. 26, 2018,the contents of which are hereby incorporated by reference herein intheir entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to a wireless power transmission systemand, more particularly, to a method and apparatus for transmitting orreceiving data.

Related Art

A contactless wireless charging method is an energy transfer method forelectromagnetically transferring energy without using a wire in a methodfor sending energy through an existing wire so that the energy is usedas power for an electronic device. The contactless wireless transmissionmethod includes an electromagnetic induction method and a resonantmethod. In the electromagnetic induction method, a power transmissionunit generates a magnetic field through a power transmission coil (i.e.,a primary coil), and a power reception coil (i.e., a secondary coil) isplaced at the location where an electric current may be induced so thatpower is transferred. In the resonant method, energy is transmittedusing a resonant phenomenon between the transmission coil and thereception coil. In this case, a system is configured so that the primarycoil and the secondary coil have the same resonant frequency, andresonant mode energy coupling between the transmission and receptioncoils is used.

A wireless power transmission system may include a message exchangefunction of an application layer for supporting an extension to variousapplication fields. Based on the function, authentication relatedinformation or other information on an application level of a device maybe transmitted and received between a wireless power transmission deviceand a wireless power reception device. In order for the messages of ahigher layer to be exchanged between a wireless power transmissionapparatus and reception apparatus as described above, separatehierarchical architecture for data transmission may be configured. Thereis a need for a protocol through which such higher layer messages orhigher layer data can be effectively exchanged.

Meanwhile, the wireless power transmission system supports powerloss-based foreign object detection (FOD). However, if timing at whichthe wireless power transmission apparatus measures transmission powerand timing at which the wireless power reception apparatus measuresreceived power are not synchronized, there is problem in that it isdifficult to calculate an accurate power loss. Furthermore, the wirelesspower transmission apparatus has to cumulatively calculate transmissionpower every offset because it is difficult to accurately predict timingat which the wireless power transmission apparatus receives a receivedpower packet from the wireless power reception apparatus. This resultsin the waste of processing resources of the wireless power transmissionapparatus. Accordingly, there is a need for a method of synchronizingpieces of timing at which a power loss is calculated between thewireless power transmission apparatus and reception apparatus.

SUMMARY OF THE DISCLOSURE

The present disclosure provides a wireless power transmission apparatusand method and a wireless power reception apparatus and method, whichtransmit information informing whether the bidirectional transmission ofhigher layer data is supported.

The present disclosure also provides a wireless power transmissionapparatus and method and a wireless power reception apparatus andmethod, which receive information informing whether the bidirectionaltransmission of higher layer data is supported.

The present disclosure also provides a wireless power receptionapparatus and method for transmitting a packet that synchronizes timingat which a power loss is calculated.

The present disclosure also provides a wireless power transmissionapparatus and method for receiving a packet that synchronizes timing atwhich a power loss is calculated.

In an aspect, a wireless power reception apparatus includes a powerpickup circuit configured to receive, from a wireless power transmissionapparatus, wireless power generated based on magnetic coupling in apower transfer phase and a communication/control circuit configured totransmit, to a wireless power transmission apparatus, a configurationpacket including first duplex data stream information informing whethera data stream outgoing to the wireless power transmission apparatus anda data stream incoming from the wireless power transmission apparatusare simultaneously supported and to receive, from the wireless powertransmission apparatus, a capability packet including second duplex datastream information informing whether the wireless power transmissionapparatus simultaneously supports a data stream outgoing from thewireless power transmission apparatus to the wireless power receptionapparatus and a data stream incoming from the wireless power receptionapparatus to the wireless power transmission apparatus.

In an aspect, in case the first duplex data stream information informsthe simultaneous support and the second duplex data stream informationinforms the simultaneous support, the communication/control circuit maybe configured to transmit a first data stream to the wireless powertransmission apparatus and simultaneously receive a second data streamfrom the wireless power transmission apparatus.

In another aspect, in case at least one of the first duplex data streaminformation and the second duplex data stream information does notinform the simultaneous support, the communication/control circuit maybe configured to open any one of a first data stream to the wirelesspower transmission apparatus or a second data stream from the wirelesspower transmission apparatus.

In still another aspect, each of the first duplex data streaminformation and the second duplex data stream information may informthat data streams are simultaneously supported or not simultaneouslysupported using 1 bit.

In still another aspect, the communication/control circuit may transmit,to the wireless power transmission apparatus, a timing packet informinga start of a window (t_window) providing a time interval in which thereceived wireless power may be calculated.

In another aspect, a wireless power transmission apparatus includes apower conversion circuit configured to transmit, to a wireless powerreception apparatus, wireless power generated based on magnetic couplingin a power transfer phase and a communication/control circuit configuredto transmit, to the wireless power reception apparatus, a capabilitypacket including first duplex data stream information informing whethera data stream outgoing to the wireless power reception apparatus and adata stream incoming from the wireless power reception apparatus aresimultaneously supported and to receive, from the wireless powerreception apparatus, a configuration packet including second duplex datastream information informing whether the wireless power receptionapparatus simultaneously supports a data stream outgoing from thewireless power reception apparatus to the wireless power transmissionapparatus and a data stream incoming from the wireless powertransmission apparatus to the wireless power reception apparatus.

In an aspect, in case the first duplex data stream information informsthe simultaneous support and the second duplex data stream informationinform the simultaneous support, the communication/control circuit maybe configured to transmit a first data stream to the wireless powerreception apparatus and simultaneously receive a second data stream fromthe wireless power reception apparatus.

In another aspect, in case at least one of the first duplex data streaminformation and the second duplex data stream information does notinform the simultaneous support, the communication/control circuit maybe configured to open any one of a first data stream to the wirelesspower reception apparatus or a second data stream from the wirelesspower reception apparatus.

In still another aspect, each of the first duplex data streaminformation and the second duplex data stream information may informthat data streams are simultaneously supported or not simultaneouslysupported using 1 bit.

In still another aspect, the communication/control circuit may receive,from the wireless power reception apparatus, a timing packet informing astart of a window (t_window) providing a time interval in which thetransmitted wireless power may be calculated.

Higher layer data can be effectively exchanged because the wirelesspower transmission apparatus and the wireless power reception apparatusclearly recognize the bidirectional transmission of higher layer data.The accuracy of a power loss and a reduction of processing resources canbe achieved because pieces of timing at which a power loss is calculatedare synchronized between the wireless power transmission apparatus andreception apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless power system (10) according toan exemplary embodiment of the present disclosure.

FIG. 2 is a block diagram of a wireless power system (10) according toanother exemplary embodiment of the present disclosure.

FIG. 3A shows an exemplary embodiment of diverse electronic devicesadopting a wireless power transfer system.

FIG. 3B shows an example of a WPC NDEF in a wireless power transfersystem.

FIG. 4A is a block diagram of a wireless power transfer system accordingto another exemplary embodiment of the present disclosure.

FIG. 4B is a diagram illustrating an example of a Bluetoothcommunication architecture to which an embodiment according to thepresent disclosure may be applied.

FIG. 4C is a block diagram illustrating a wireless power transfer systemusing BLE communication according to an example.

FIG. 4D is a block diagram illustrating a wireless power transfer systemusing BLE communication according to another example.

FIG. 5 is a state transition diagram for describing a wireless powertransfer procedure.

FIG. 6 shows a power control method according to an exemplary embodimentof the present disclosure.

FIG. 7 is a block diagram of a wireless power transmitter according toanother exemplary embodiment of the present disclosure.

FIG. 8 shows a wireless power receiver according to another exemplaryembodiment of the present disclosure.

FIG. 9 shows a communication frame structure according to an exemplaryembodiment of the present disclosure.

FIG. 10 is a structure of a sync pattern according to an exemplaryembodiment of the present disclosure.

FIG. 11 shows operation statuses of a wireless power transmitter and awireless power receiver in a shared mode according to an exemplaryembodiment of the present disclosure.

FIG. 12 shows an application-level data stream between a wireless powertransmitter and a wireless power receiver according to an example.

FIG. 13 illustrates a hierarchical architecture for transmitting a datastream between a wireless power transmission device and a wireless powerreception device.

FIG. 14 is a flowchart illustrating a method of transmitting a datastream according to an example.

FIG. 15 is a configuration packet including duplex data streaminformation according to an example.

FIG. 16 is a capability packet including duplex data stream informationaccording to an example.

FIG. 17 illustrates timing at which a wireless power reception apparatuscalculates received power according to an example.

FIG. 18 illustrates timing at which a wireless power transmissionapparatus calculates transmission power according to an example.

FIG. 19 illustrates a method of operating a timing packet according toan example.

FIG. 20 illustrates a timing packet according to an example.

FIG. 21 illustrates a timing packet according to another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The term “wireless power”, which will hereinafter be used in thisspecification, will be used to refer to an arbitrary form of energy thatis related to an electric field, a magnetic field, and anelectromagnetic field, which is transferred (or transmitted) from awireless power transmitter to a wireless power receiver without usingany physical electromagnetic conductors. The wireless power may also bereferred to as a wireless power signal, and this may refer to anoscillating magnetic flux that is enclosed by a primary coil and asecondary coil. For example, power conversion for wirelessly chargingdevices including mobile phones, cordless phones, iPods, MP3 players,headsets, and so on, within the system will be described in thisspecification. Generally, the basic principle of the wireless powertransfer technique includes, for example, all of a method oftransferring power by using magnetic coupling, a method of transferringpower by using radio frequency (RF), a method of transferring power byusing microwaves, and a method of transferring power by using ultrasound(or ultrasonic waves).

FIG. 1 is a block diagram of a wireless power system (10) according toan exemplary embodiment of the present disclosure.

Referring to FIG. 1 , the wireless power system (10) include a wirelesspower transmitter (100) and a wireless power receiver (200).

The wireless power transmitter (100) is supplied with power from anexternal power source (S) and generates a magnetic field. The wirelesspower receiver (200) generates electric currents by using the generatedmagnetic field, thereby being capable of wirelessly receiving power.

Additionally, in the wireless power system (10), the wireless powertransmitter (100) and the wireless power receiver (200) may transceive(transmit and/or receive) diverse information that is required for thewireless power transfer. Herein, communication between the wirelesspower transmitter (100) and the wireless power receiver (200) may beperformed (or established) in accordance with any one of an in-bandcommunication, which uses a magnetic field that is used for the wirelesspower transfer (or transmission), and an out-band communication, whichuses a separate communication carrier. Out-band communication may alsobe referred to as out-of-band communication. Hereinafter, out-bandcommunication will be largely described. Examples of out-bandcommunication may include NFC, Bluetooth, Bluetooth low energy (BLE),and the like.

Herein, the wireless power transmitter (100) may be provided as a fixedtype or a mobile (or portable) type. Examples of the fixed transmittertype may include an embedded type, which is embedded in in-door ceilingsor wall surfaces or embedded in furniture, such as tables, an implantedtype, which is installed in out-door parking lots, bus stops, subwaystations, and so on, or being installed in means of transportation, suchas vehicles or trains. The mobile (or portable) type wireless powertransmitter (100) may be implemented as a part of another device, suchas a mobile device having a portable size or weight or a cover of alaptop computer, and so on.

Additionally, the wireless power receiver (200) should be interpreted asa comprehensive concept including diverse home appliances and devicesthat are operated by being wirelessly supplied with power instead ofdiverse electronic devices being equipped with a battery and a powercable. Typical examples of the wireless power receiver (200) may includeportable terminals, cellular phones, smartphones, personal digitalassistants (PDAs), portable media players (PDPs), Wibro terminals,tablet PCs, phablet, laptop computers, digital cameras, navigationterminals, television, electronic vehicles (EVs), and so on.

In the wireless power system (10), one wireless power receiver (200) ora plurality of wireless power receivers may exist. Although it is shownin FIG. 1 that the wireless power transmitter (100) and the wirelesspower receiver (200) send and receive power to and from one another in aone-to-one correspondence (or relationship), as shown in FIG. 2 , it isalso possible for one wireless power transmitter (100) to simultaneouslytransfer power to multiple wireless power receivers (200-1, 200-2, . . ., 200-M). Most particularly, in case the wireless power transfer (ortransmission) is performed by using a magnetic resonance method, onewireless power transmitter (100) may transfer power to multiple wirelesspower receivers (200-1, 200-2, . . . , 200-M) by using a synchronizedtransport (or transfer) method or a time-division transport (ortransfer) method.

Additionally, although it is shown in FIG. 1 that the wireless powertransmitter (100) directly transfers (or transmits) power to thewireless power receiver (200), the wireless power system (10) may alsobe equipped with a separate wireless power transceiver, such as a relayor repeater, for increasing a wireless power transport distance betweenthe wireless power transmitter (100) and the wireless power receiver(200). In this case, power is delivered to the wireless powertransceiver from the wireless power transmitter (100), and, then, thewireless power transceiver may transfer the received power to thewireless power receiver (200).

Hereinafter, the terms wireless power receiver, power receiver, andreceiver, which are mentioned in this specification, will refer to thewireless power receiver (200). Also, the terms wireless powertransmitter, power transmitter, and transmitter, which are mentioned inthis specification, will refer to the wireless power transmitter (100).

FIG. 3 shows an exemplary embodiment of diverse electronic devicesadopting a wireless power transfer system.

As shown in FIG. 3 , the electronic devices included in the wirelesspower transfer system are sorted in accordance with the amount oftransmitted power and the amount of received power. Referring to FIG. 3, wearable devices, such as smart watches, smart glasses, head mounteddisplays (HMDs), smart rings, and so on, and mobile electronic devices(or portable electronic devices), such as earphones, remote controllers,smartphones, PDAs, tablet PCs, and so on, may adopt a low-power(approximately 5 W or less or approximately 20 W or less) wirelesscharging method.

Small-sized/Mid-sized electronic devices, such as laptop computers,robot vacuum cleaners, TV receivers, audio devices, vacuum cleaners,monitors, and so on, may adopt a mid-power (approximately 50 W or lessor approximately 200 W or less) wireless charging method. Kitchenappliances, such as mixers, microwave ovens, electric rice cookers, andso on, and personal transportation devices (or other electric devices ormeans of transportation), such as powered wheelchairs, powered kickscooters, powered bicycles, electric cars, and so on may adopt ahigh-power (approximately 2 kW or less or approximately 22 kW or less)wireless charging method.

The electric devices or means of transportation, which are describedabove (or shown in FIG. 1 ) may each include a wireless power receiver,which will hereinafter be described in detail. Therefore, theabove-described electric devices or means of transportation may becharged (or re-charged) by wirelessly receiving power from a wirelesspower transmitter.

Hereinafter, although the present disclosure will be described based ona mobile device adopting the wireless power charging method, this ismerely exemplary. And, therefore, it shall be understood that thewireless charging method according to the present disclosure may beapplied to diverse electronic devices.

A standard for the wireless power transfer (or transmission) includes awireless power consortium (WPC), an air fuel alliance (AFA), and a powermatters alliance (PMA).

The WPC standard defines a baseline power profile (BPP) and an extendedpower profile (EPP). The BPP is related to a wireless power transmitterand a wireless power receiver supporting a power transfer of SW, and theEPP is related to a wireless power transmitter and a wireless powerreceiver supporting the transfer of a power range greater than SW andless than 30 W.

Diverse wireless power transmitters and wireless power receivers eachusing a different power level may be covered by each standard and may besorted by different power classes or categories.

For example, the WPC may categorize (or sort) the wireless powertransmitters and the wireless power receivers as PC-1, PC0, PC1, andPC2, and the WPC may provide a standard document (or specification) foreach power class (PC). The PC-1 standard relates to wireless powertransmitters and receivers providing a guaranteed power of less than 5W. The application of PC-1 includes wearable devices, such as smartwatches.

The PC0 standard relates to wireless power transmitters and receiversproviding a guaranteed power of 5 W. The PC0 standard includes an EPPhaving a guaranteed power ranges that extends to 30 W. Although in-band(IB) communication corresponds to a mandatory communication protocol ofPC0, out-of-band (OB) communication that is used as an optional backupchannel may also be used for PC0. The wireless power receiver may beidentified by setting up an OB flag, which indicates whether or not theOB is supported, within a configuration packet. A wireless powertransmitter supporting the OB may enter an OB handover phase bytransmitting a bit-pattern for an OB handover as a response to theconfiguration packet. The response to the configuration packet maycorrespond to an NAK, an ND, or an 8-bit pattern that is newly defined.The application of the PC0 includes smartphones.

The PC1 standard relates to wireless power transmitters and receiversproviding a guaranteed power ranging from 30 W to 150 W. OB correspondsto a mandatory communication channel for PC1, and D3 is used forinitialization and link establishment to OB. The wireless powertransmitter may enter an OB handover phase by transmitting a bit-patternfor an OB handover as a response to the configuration packet. Theapplication of the PC1 includes laptop computers or power tools.

The PC2 standard relates to wireless power transmitters and receiversproviding a guaranteed power ranging from 200 W to 2 kW, and itsapplication includes kitchen appliances.

As described above, the PCs may be differentiated in accordance with therespective power levels. And, information on whether or not thecompatibility between the same PCs is supported may be optional ormandatory. Herein, the compatibility between the same PCs indicates thatpower transfer/reception between the same PCs is possible. For example,in case a wireless power transmitter corresponding to PC x is capable ofperforming charging of a wireless power receiver having the same PC x,it may be understood that compatibility is maintained between the samePCs. Similarly, compatibility between different PCs may also besupported. Herein, the compatibility between different PCs indicatesthat power transfer/reception between different PCs is also possible.For example, in case a wireless power transmitter corresponding to PC xis capable of performing charging of a wireless power receiver having PCy, it may be understood that compatibility is maintained between thedifferent PCs.

The support of compatibility between PCs corresponds to an extremelyimportant issue in the aspect of user experience and establishment ofinfrastructure. Herein, however, diverse problems, which will bedescribed below, exist in maintaining the compatibility between PCs.

In case of the compatibility between the same PCs, for example, in caseof a wireless power receiver using a lap-top charging method, whereinstable charging is possible only when power is continuously transferred,even if its respective wireless power transmitter has the same PC, itmay be difficult for the corresponding wireless power receiver to stablyreceive power from a wireless power transmitter of the power toolmethod, which transfers power non-continuously. Additionally, in case ofthe compatibility between different PCs, for example, in case a wirelesspower transmitter having a minimum guaranteed power of 200 W transferspower to a wireless power receiver having a maximum guaranteed power of5 W, the corresponding wireless power receiver may be damaged due to anovervoltage. As a result, it may be inappropriate (or difficult) to usethe PS as an index/reference standard representing/indicating thecompatibility.

Wireless power transmitters and receivers may provide a very convenientuser experience and interface (UX/UI). That is, a smart wirelesscharging service may be provided, and the smart wireless chargingservice may be implemented based on a UX/UI of a smartphone including awireless power transmitter. For these applications, an interface betweena processor of a smartphone and a wireless charging receiver allows for“drop and play” two-way communication between the wireless powertransmitter and the wireless power receiver.

As an example, a user may experience a smart wireless charging servicein a hotel. When the user enters a hotel room and puts a smartphone on awireless charger in the room, the wireless charger transmits wirelesspower to the smartphone and the smartphone receives wireless power. Inthis process, the wireless charger transmits information on the smartwireless charging service to the smartphone. When it is detected thatthe smartphone is located on the wireless charger, when it is detectedthat wireless power is received, or when the smartphone receivesinformation on the smart wireless charging service from the wirelesscharger, the smartphone enters a state of inquiring the user aboutagreement (opt-in) of supplemental features. To this end, the smartphonemay display a message on a screen in a manner with or without an alarmsound. An example of the message may include the phrase “Welcome to ###hotel. Select” Yes” to activate smart charging functions: Yes|NoThanks.” The smartphone receives an input from the user who selects Yesor No Thanks, and performs a next procedure selected by the user. If Yesis selected, the smartphone transmits corresponding information to thewireless charger. The smartphone and the wireless charger perform thesmart charging function together.

The smart wireless charging service may also include receiving WiFicredentials auto-filled. For example, the wireless charger transmits theWiFi credentials to the smartphone, and the smartphone automaticallyinputs the WiFi credentials received from the wireless charger byrunning an appropriate application.

The smart wireless charging service may also include running a hotelapplication that provides hotel promotions or obtaining remotecheck-in/check-out and contact information.

As another example, the user may experience the smart wireless chargingservice in a vehicle. When the user gets in the vehicle and puts thesmartphone on the wireless charger, the wireless charger transmitswireless power to the smartphone and the smartphone receives wirelesspower. In this process, the wireless charger transmits information onthe smart wireless charging service to the smartphone. When it isdetected that the smartphone is located on the wireless charger, whenwireless power is detected to be received, or when the smartphonereceives information on the smart wireless charging service from thewireless charger, the smartphone enters a state of inquiring the userabout checking identity.

In this state, the smartphone is automatically connected to the vehiclevia WiFi and/or Bluetooth. The smartphone may display a message on thescreen in a manner with or without an alarm sound. An example of themessage may include a phrase of “Welcome to your car. Select “Yes” tosynch device with in-car controls: Yes|No Thanks.” Upon receiving theuser's input to select Yes or No Thanks, the smartphone performs a nextprocedure selected by the user. If Yes is selected, the smartphonetransmits corresponding information to the wireless charger. Inaddition, the smartphone and the wireless charger may run an in-vehiclesmart control function together by driving in-vehicleapplication/display software. The user may enjoy the desired music andcheck a regular map location. The in-vehicle applications/displaysoftware may include an ability to provide synchronous access forpassers-by.

As another example, the user may experience smart wireless charging athome. When the user enters the room and puts the smartphone on thewireless charger in the room, the wireless charger transmits wirelesspower to the smartphone and the smartphone receives wireless power. Inthis process, the wireless charger transmits information on the smartwireless charging service to the smartphone. When it is detected thatthe smartphone is located on the wireless charger, when wireless poweris detected to be received, or when the smartphone receives informationon the smart wireless charging service from the wireless charger, thesmartphone enters a state of inquiring the user about agreement (opt-in)of supplemental features. To this end, the smartphone may display amessage on the screen in a manner with or without an alarm sound. Anexample of the message may include a phrase such as “Hi xxx, Would youlike to activate night mode and secure the building?: Yes|No Thanks.”The smartphone receives a user input to select Yes or No Thanks andperforms a next procedure selected by the user. If Yes is selected, thesmartphone transmits corresponding information to the wireless charger.The smartphones and the wireless charger may recognize at least user'spattern and recommend the user to lock doors and windows, turn offlights, or set an alarm.

Hereinafter, ‘profiles’ will be newly defined based on indexes/referencestandards representing/indicating the compatibility. More specifically,it may be understood that by maintaining compatibility between wirelesspower transmitters and receivers having the same ‘profile’, stable powertransfer/reception may be performed, and that power transfer/receptionbetween wireless power transmitters and receivers having different‘profiles’ cannot be performed. The ‘profiles’ may be defined inaccordance with whether or not compatibility is possible and/or theapplication regardless of (or independent from) the power class.

For example, the profile may be sorted into 3 different categories, suchas i) Mobile, ii) Power tool and iii) Kitchen.

For another example, the profile may be sorted into 4 differentcategories, such as i) Mobile, ii) Power tool, iii) Kitchen, and iv)Wearable.

In case of the ‘Mobile’ profile, the PC may be defined as PC0 and/orPC1, the communication protocol/method may be defined as D3 and OBcommunication, and the operation frequency may be defined as 87 to 205kHz, and smartphones, laptop computers, and so on, may exist as theexemplary application.

In case of the ‘Power tool’ profile, the PC may be defined as PC1, thecommunication protocol/method may be defined as D3 communication, andthe operation frequency may be defined as 87 to 145 kHz, and powertools, and so on, may exist as the exemplary application.

In case of the ‘Kitchen’ profile, the PC may be defined as PC2, thecommunication protocol/method may be defined as NFC-based communication,and the operation frequency may be defined as less than 100 kHz, andkitchen/home appliances, and so on, may exist as the exemplaryapplication.

In the case of power tools and kitchen profiles, NFC communication maybe used between the wireless power transmitter and the wireless powerreceiver. The wireless power transmitter and the wireless power receivermay confirm that they are NFC devices with each other by exchanging WPCNFC data exchange profile format (NDEF). The WPC NDEF may include, forexample, an application profile field (e.g., 1B), a version field (e.g.,1B), and profile specific data (e.g., 1B). The application profile fieldindicates whether the corresponding device is i) mobile and computing,ii) power tool, and iii) kitchen, and an upper nibble in the versionfield indicates a major version and a lower nibble indicates a minorversion. In addition, profile-specific data defines content for thekitchen.

In case of the ‘Wearable’ profile, the PC may be defined as PC-1, thecommunication protocol/method may be defined as D3 communication, andthe operation frequency may be defined as 87 to 205 kHz, and wearabledevices that are worn by the users, and so on, may exist as theexemplary application.

It may be mandatory to maintain compatibility between the same profiles,and it may be optional to maintain compatibility between differentprofiles.

The above-described profiles (Mobile profile, Power tool profile,Kitchen profile, and Wearable profile) may be generalized and expressedas first to nth profile, and a new profile may be added/replaced inaccordance with the WPC standard and the exemplary embodiment.

In case the profile is defined as described above, the wireless powertransmitter may optionally perform power transfer only to the wirelesspower receiving corresponding to the same profile as the wireless powertransmitter, thereby being capable of performing a more stable powertransfer. Additionally, since the load (or burden) of the wireless powertransmitter may be reduced and power transfer is not attempted to awireless power receiver for which compatibility is not possible, therisk of damage in the wireless power receiver may be reduced.

PC1 of the ‘Mobile’ profile may be defined by being derived from anoptional extension, such as OB, based on PC0. And, the ‘Power tool’profile may be defined as a simply modified version of the PC1 ‘Mobile’profile. Additionally, up until now, although the profiles have beendefined for the purpose of maintaining compatibility between the sameprofiles, in the future, the technology may be evolved to a level ofmaintaining compatibility between different profiles. The wireless powertransmitter or the wireless power receiver may notify (or announce) itsprofile to its counterpart by using diverse methods.

In the AFA standard, the wireless power transmitter is referred to as apower transmitting unit (PTU), and the wireless power receiver isreferred to as a power receiving unit (PRU). And, the PTU is categorizedto multiple classes, as shown in Table 1, and the PRU is categorized tomultiple classes, as shown in Table 2.

TABLE 1 Minimum category Minimum value for support a maximum number PTUP_(TX) _(—) _(IN) _(—) _(MAX) requirement of supported devices Class 1 2 W 1x Category 1 1x Category 1 Class 2 10 W 1x Category 3 2x Category2 Class 3 16 W 1x Category 4 2x Category 3 Class 4 33 W 1x Category 5 3xCategory 3 Class 5 50 W 1x Category 6 4x Category 3 Class 6 70 W 1xCategory 7 5x Category 3

TABLE 2 PRU P_(RX) _(—) _(OUT) _(—) _(MAX′) Exemplary applicationCategory 1 TBD Bluetooth headset Category 2 3.5 W Feature phone Category3 6.5 W Smartphone Category 4 13 W Tablet PC, Phablet Category 5 25 WSmall form factor laptop Category 6 37.5 W General laptop Category 7 50W Home appliance

As shown in Table 1, a maximum output power capability of Class n PTUmay be equal to or greater than the P_(TX_IN_MAX) of the correspondingclass. The PRU cannot draw a power that is higher than the power levelspecified in the corresponding category.

FIG. 4 a is a block diagram of a wireless power transfer systemaccording to another exemplary embodiment of the present disclosure.

Referring to FIG. 4 a , the wireless power transfer system (10) includesa mobile device (450), which wirelessly receives power, and a basestation (400), which wirelessly transmits power.

As a device providing induction power or resonance power, the basestation (400) may include at least one of a wireless power transmitter(100) and a system unit (405). The wireless power transmitter (100) maytransmit induction power or resonance power and may control thetransmission. The wireless power transmitter (100) may include a powerconversion unit (110) converting electric energy to a power signal bygenerating a magnetic field through a primary coil (or primary coils),and a communications & control unit (120) controlling the communicationand power transfer between the wireless power receiver (200) in order totransfer power at an appropriate (or suitable) level. The system unit(405) may perform input power provisioning, controlling of multiplewireless power transmitters, and other operation controls of the basestation (400), such as user interface control.

The primary coil may generate an electromagnetic field by using analternating current power (or voltage or current). The primary coil issupplied with an alternating current power (or voltage or current) of aspecific frequency, which is being outputted from the power conversionunit (110). And, accordingly, the primary coil may generate a magneticfield of the specific frequency. The magnetic field may be generated ina non-radial shape or a radial shape. And, the wireless power receiver(200) receives the generated magnetic field and then generates anelectric current. In other words, the primary coil wirelessly transmitspower.

In the magnetic induction method, a primary coil and a secondary coilmay have randomly appropriate shapes. For example, the primary coil andthe secondary coil may correspond to copper wire being wound around ahigh-permeability formation, such as ferrite or a non-crystalline metal.The primary coil may also be referred to as a transmitting coil, aprimary core, a primary winding, a primary loop antenna, and so on.Meanwhile, the secondary coil may also be referred to as a receivingcoil, a secondary core, a secondary winding, a secondary loop antenna, apickup antenna, and so on.

In case of using the magnetic resonance method, the primary coil and thesecondary coil may each be provided in the form of a primary resonanceantenna and a secondary resonance antenna. The resonance antenna mayhave a resonance structure including a coil and a capacitor. At thispoint, the resonance frequency of the resonance antenna may bedetermined by the inductance of the coil and a capacitance of thecapacitor. Herein, the coil may be formed to have a loop shape. And, acore may be placed inside the loop. The core may include a physicalcore, such as a ferrite core, or an air core.

The energy transmission (or transfer) between the primary resonanceantenna and the second resonance antenna may be performed by a resonancephenomenon occurring in the magnetic field. When a near fieldcorresponding to a resonance frequency occurs in a resonance antenna,and in case another resonance antenna exists near the correspondingresonance antenna, the resonance phenomenon refers to a highly efficientenergy transfer occurring between the two resonance antennas that arecoupled with one another. When a magnetic field corresponding to theresonance frequency is generated between the primary resonance antennaand the secondary resonance antenna, the primary resonance antenna andthe secondary resonance antenna resonate with one another. And,accordingly, in a general case, the magnetic field is focused toward thesecond resonance antenna at a higher efficiency as compared to a casewhere the magnetic field that is generated from the primary antenna isradiated to a free space. And, therefore, energy may be transferred tothe second resonance antenna from the first resonance antenna at a highefficiency. The magnetic induction method may be implemented similarlyto the magnetic resonance method. However, in this case, the frequencyof the magnetic field is not required to be a resonance frequency.Nevertheless, in the magnetic induction method, the loops configuringthe primary coil and the secondary coil are required to match oneanother, and the distance between the loops should be very close-ranged.

Although it is not shown in the drawing, the wireless power transmitter(100) may further include a communication antenna. The communicationantenna may transmit and/or receive a communication signal by using acommunication carrier apart from the magnetic field communication. Forexample, the communication antenna may transmit and/or receivecommunication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE,ZigBee, NFC, and so on.

The communications & control unit (120) may transmit and/or receiveinformation to and from the wireless power receiver (200). Thecommunications & control unit (120) may include at least one of an IBcommunication module and an OB communication module.

The IB communication module may transmit and/or receive information byusing a magnetic wave, which uses a specific frequency as its centerfrequency. For example, the communications & control unit (120) mayperform in-band (IB) communication by transmitting communicationinformation on the operating frequency of wireless power transferthrough the primary coil or by receiving communication information onthe operating frequency through the primary coil. At this point, thecommunications & control unit (120) may load information in the magneticwave or may interpret the information that is carried by the magneticwave by using a modulation scheme, such as binary phase shift keying(BPSK), or amplitude shift keying (ASK), and so on, or a coding scheme,such as Manchester coding or non-return-to-zero level (NZR-L) coding,and so on. By using the above-described D3 communication, thecommunications & control unit (120) may transmit and/or receiveinformation to distances of up to several meters at a data transmissionrate of several kbps.

The OB communication module may also perform out-of-band communicationthrough a communication antenna. For example, the communications &control unit (120) may be provided to a near field communication module.Examples of the near field communication module may includecommunication modules, such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee,NFC, and so on.

The communications & control unit (120) may control the overalloperations of the wireless power transmitter (100). The communications &control unit (120) may perform calculation and processing of diverseinformation and may also control each configuration element of thewireless power transmitter (100).

The communications & control unit (120) may be implemented in a computeror a similar device as hardware, software, or a combination of the same.When implemented in the form of hardware, the communications & controlunit (120) may be provided as an electronic circuit performing controlfunctions by processing electrical signals. And, when implemented in theform of software, the communications & control unit (120) may beprovided as a program that operates the communications & control unit(120).

By controlling the operating point, the communications & control unit(120) may control the transmitted power. The operating point that isbeing controlled may correspond to a combination of a frequency (orphase), a duty cycle, a duty ratio, and a voltage amplitude. Thecommunications & control unit (120) may control the transmitted power byadjusting any one of the frequency (or phase), the duty cycle, the dutyratio, and the voltage amplitude. Additionally, the wireless powertransmitter (100) may supply a consistent level of power, and thewireless power receiver (200) may control the level of received power bycontrolling the resonance frequency.

The mobile device (450) includes a wireless power receiver (200)receiving wireless power through a secondary coil, and a load (455)receiving and storing the power that is received by the wireless powerreceiver (200) and supplying the received power to the device.

The wireless power receiver (200) may include a power pick-up unit (210)and a communications & control unit (220). The power pick-up unit (210)may receive wireless power through the secondary coil and may convertthe received wireless power to electric energy. The power pick-up unit(210) rectifies the alternating current (AC) signal, which is receivedthrough the secondary coil, and converts the rectified signal to adirect current (DC) signal. The communications & control unit (220) maycontrol the transmission and reception of the wireless power (transferand reception of power).

The secondary coil may receive wireless power that is being transmittedfrom the wireless power transmitter (100). The secondary coil mayreceive power by using the magnetic field that is generated in theprimary coil. Herein, in case the specific frequency corresponds aresonance frequency, magnetic resonance may occur between the primarycoil and the secondary coil, thereby allowing power to be transferredwith greater efficiency.

Although it is not shown in FIG. 4 a , the communications & control unit(220) may further include a communication antenna. The communicationantenna may transmit and/or receive a communication signal by using acommunication carrier apart from the magnetic field communication. Forexample, the communication antenna may transmit and/or receivecommunication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE,ZigBee, NFC, and so on.

The communications & control unit (220) may transmit and/or receiveinformation to and from the wireless power transmitter (100). Thecommunications & control unit (220) may include at least one of an IBcommunication module and an OB communication module.

The IB communication module may transmit and/or receive information byusing a magnetic wave, which uses a specific frequency as its centerfrequency. For example, the communications & control unit (220) mayperform D3 communication by loading information in the magnetic wave andby transmitting the information through the secondary coil or byreceiving a magnetic wave carrying information through the secondarycoil. At this point, the communications & control unit (120) may loadinformation in the magnetic wave or may interpret the information thatis carried by the magnetic wave by using a modulation scheme, such asbinary phase shift keying (BPSK) or amplitude shift keying (ASK), and soon, or a coding scheme, such as Manchester coding or non-return-to-zerolevel (NZR-L) coding, and so on. By using the above-described IBcommunication, the communications & control unit (220) may transmitand/or receive information to distances of up to several meters at adata transmission rate of several kbps.

The OB communication module may also perform out-of-band communicationthrough a communication antenna. For example, the communications &control unit (220) may be provided to a near field communication module.

Examples of the near field communication module may includecommunication modules, such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee,NFC, and so on.

The communications & control unit (220) may control the overalloperations of the wireless power receiver (200). The communications &control unit (220) may perform calculation and processing of diverseinformation and may also control each configuration element of thewireless power receiver (200).

The communications & control unit (220) may be implemented in a computeror a similar device as hardware, software, or a combination of the same.When implemented in the form of hardware, the communications & controlunit (220) may be provided as an electronic circuit performing controlfunctions by processing electrical signals. And, when implemented in theform of software, the communications & control unit (220) may beprovided as a program that operates the communications & control unit(220).

When the communication/control circuit 120 and the communication/controlcircuit 220 are Bluetooth or Bluetooth LE as an OB communication moduleor a short-range communication module, the communication/control circuit120 and the communication/control circuit 220 may each be implementedand operated with a communication architecture as shown in FIG. 4B.

FIG. 4B is a diagram illustrating an example of a Bluetoothcommunication architecture to which an embodiment according to thepresent disclosure may be applied.

Referring to FIG. 4B, (a) of FIG. 4B shows an example of a protocolstack of Bluetooth basic rate (BR)/enhanced data rate (EDR) supportingGATT, and (b) shows an example of Bluetooth low energy (BLE) protocolstack.

Specifically, as shown in (a) of FIG. 4B, the Bluetooth BR/EDR protocolstack may include an upper control stack 460 and a lower host stack 470based on a host controller interface (HCI) 18.

The host stack (or host module) 470 refers to hardware for transmittingor receiving a Bluetooth packet to or from a wirelesstransmission/reception module which receives a Bluetooth signal of 2.4GHz, and the controller stack 460 is connected to the Bluetooth moduleto control the Bluetooth module and perform an operation.

The host stack 470 may include a BR/EDR PHY layer 12, a BR/EDR basebandlayer 14, and a link manager layer 16.

The BR/EDR PHY layer 12 is a layer that transmits and receives a 2.4 GHzradio signal, and in the case of using Gaussian frequency shift keying(GFSK) modulation, the BR/EDR PHY layer 12 may transmit data by hopping79 RF channels.

The BR/EDR baseband layer 14 serves to transmit a digital signal,selects a channel sequence for hopping 1400 times per second, andtransmits a time slot with a length of 625 us for each channel.

The link manager layer 16 controls an overall operation (link setup,control, security) of Bluetooth connection by utilizing a link managerprotocol (LMP).

The link manager layer 16 may perform the following functions.

Performs ACL/SCO logical transport, logical link setup, and control.

Detach: It interrupts connection and informs a counterpart device abouta reason for the interruption.

Performs power control and role switch.

Performs security (authentication, pairing, encryption) function.

The host controller interface layer 18 provides an interface between ahost module and a controller module so that a host provides commands anddata to the controller and the controller provides events and data tothe host.

The host stack (or host module, 470) includes a logical link control andadaptation protocol (L2CAP) 21, an attribute protocol 22, a genericattribute profile (GATT) 23, a generic access profile (GAP) 24, and aBR/EDR profile 25.

The logical link control and adaptation protocol (L2CAP) 21 may provideone bidirectional channel for transmitting data to a specific protocolor profile.

The L2CAP 21 may multiplex various protocols, profiles, etc., providedfrom upper Bluetooth.

L2CAP of Bluetooth BR/EDR uses dynamic channels, supports protocolservice multiplexer, retransmission, streaming mode, and providessegmentation and reassembly, per-channel flow control, and errorcontrol.

The generic attribute profile (GATT) 23 may be operable as a protocolthat describes how the attribute protocol 22 is used when services areconfigured. For example, the generic attribute profile 23 may beoperable to specify how ATT attributes are grouped together intoservices and may be operable to describe features associated withservices.

Accordingly, the generic attribute profile 23 and the attributeprotocols (ATT) 22 may use features to describe device's state andservices, how features are related to each other, and how they are used.

The attribute protocol 22 and the BR/EDR profile 25 define a service(profile) using Bluetooth BR/EDR and an application protocol forexchanging these data, and the generic access profile (GAP) 24 definesdevice discovery, connectivity, and security level.

As shown in (b) of FIG. 4B, the Bluetooth LE protocol stack includes acontroller stack 480 operable to process a wireless device interfaceimportant in timing and a host stack 490 operable to process high leveldata.

First, the controller stack 480 may be implemented using a communicationmodule that may include a Bluetooth wireless device, for example, aprocessor module that may include a processing device such as amicroprocessor.

The host stack 490 may be implemented as a part of an OS running on aprocessor module or as an instantiation of a package on the OS.

In some cases, the controller stack and the host stack may be run orexecuted on the same processing device in a processor module.

The controller stack 480 includes a physical layer (PHY) 32, a linklayer 34, and a host controller interface 36.

The physical layer (PHY, wireless transmission/reception module) 32 is alayer that transmits and receives a 2.4 GHz radio signal and usesGaussian frequency shift keying (GFSK) modulation and a frequencyhopping scheme including 40 RF channels.

The link layer 34, which serves to transmit or receive Bluetoothpackets, creates connections between devices after performingadvertising and scanning functions using 3 advertising channels andprovides a function of exchanging data packets of up to 257 bytesthrough 37 data channels.

The host stack includes a generic access profile (GAP) 45, a logicallink control and adaptation protocol (L2CAP, 41), a security manager(SM) 42, and an attribute protocol (ATT) 43, a generic attribute profile(GATT) 44, a generic access profile 45, and an LE profile 46. However,the host stack 490 is not limited thereto and may include variousprotocols and profiles.

The host stack multiplexes various protocols, profiles, etc., providedfrom upper Bluetooth using L2CAP.

First, the logical link control and adaptation protocol (L2CAP) 41 mayprovide one bidirectional channel for transmitting data to a specificprotocol or profile.

The L2CAP 41 may be operable to multiplex data between higher layerprotocols, segment and reassemble packages, and manage multicast datatransmission.

In Bluetooth LE, three fixed channels (one for signaling CH, one forsecurity manager, and one for attribute protocol) are basically used.Also, a dynamic channel may be used as needed.

Meanwhile, a basic channel/enhanced data rate (BR/EDR) uses a dynamicchannel and supports protocol service multiplexer, retransmission,streaming mode, and the like.

The security manager (SM) 42 is a protocol for authenticating devicesand providing key distribution.

The attribute protocol (ATT) 43 defines a rule for accessing data of acounterpart device in a server-client structure. The ATT has thefollowing 6 message types (request, response, command, notification,indication, confirmation).

{circle around (1)} Request and Response message: A request message is amessage for requesting specific information from the client device tothe server device, and the response message is a response message to therequest message, which is a message transmitted from the server deviceto the client device.

{circle around (2)} Command message: It is a message transmitted fromthe client device to the server device in order to indicate a command ofa specific operation. The server device does not transmit a responsewith respect to the command message to the client device.

{circle around (3)} Notification message: It is a message transmittedfrom the server device to the client device in order to notify an event,or the like. The client device does not transmit a confirmation messagewith respect to the notification message to the server device.

{circle around (4)} Indication and confirmation message: It is a messagetransmitted from the server device to the client device in order tonotify an event, or the like. Unlike the notification message, theclient device transmits a confirmation message regarding the indicationmessage to the server device.

In the present disclosure, when the GATT profile using the attributeprotocol (ATT) 43 requests long data, a value regarding a data length istransmitted to allow a client to clearly know the data length, and acharacteristic value may be received from a server by using a universalunique identifier (UUID).

The generic access profile (GAP) 45, a layer newly implemented for theBluetooth LE technology, is used to select a role for communicationbetween Bluetooth LED devices and to control how a multi-profileoperation takes place.

Also, the generic access profile (GAP) 45 is mainly used for devicediscovery, connection generation, and security procedure part, defines ascheme for providing information to a user, and defines types ofattributes as follows.

-   -   {circle around (1)} Service: It defines a basic operation of a        device by a combination of behaviors related to data    -   {circle around (2)} Include: It defines a relationship between        services    -   {circle around (3)} Characteristics: It is a data value used in        a server    -   {circle around (4)} Behavior: It is a format that may be read by        a computer defined by a UUID (value type).

The LE profile 46, including profiles dependent upon the GATT, is mainlyapplied to a Bluetooth LE device. The LE profile 46 may include, forexample, Battery, Time, FindMe, Proximity, Time, Object DeliveryService, and the like, and details of the GATT-based profiles are asfollows.

-   -   {circle around (1)} Battery: Battery information exchanging        method    -   {circle around (2)} Time: Time information exchanging method    -   {circle around (3)} FindMe: Provision of alarm service according        to distance    -   {circle around (4)} Proximity: Battery information exchanging        method    -   {circle around (5)} Time: Time information exchanging method

The generic attribute profile (GATT) 44 may operate as a protocoldescribing how the attribute protocol (ATT) 43 is used when services areconfigured. For example, the GATT 44 may operate to define how ATTattributes are grouped together with services and operate to describefeatures associated with services.

Thus, the GATT 44 and the ATT 43 may use features in order to describestatus and services of a device and describe how the features arerelated and used.

Hereinafter, procedures of the Bluetooth low energy (BLE) technologywill be briefly described.

The BLE procedure may be classified as a device filtering procedure, anadvertising procedure, a scanning procedure, a discovering procedure,and a connecting procedure.

Device Filtering Procedure

The device filtering procedure is a method for reducing the number ofdevices performing a response with respect to a request, indication,notification, and the like, in the controller stack.

When requests are received from all the devices, it is not necessary torespond thereto, and thus, the controller stack may perform control toreduce the number of transmitted requests to reduce power consumption.

An advertising device or scanning device may perform the devicefiltering procedure to limit devices for receiving an advertisingpacket, a scan request or a connection request.

Here, the advertising device refers to a device transmitting anadvertising event, that is, a device performing an advertisement and isalso termed an advertiser.

The scanning device refers to a device performing scanning, that is, adevice transmitting a scan request.

In the BLE, in a case in which the scanning device receives someadvertising packets from the advertising device, the scanning deviceshould transmit a scan request to the advertising device.

However, in a case in which a device filtering procedure is used so ascan request transmission is not required, the scanning device maydisregard the advertising packets transmitted from the advertisingdevice.

Even in a connection request process, the device filtering procedure maybe used. In a case in which device filtering is used in the connectionrequest process, it is not necessary to transmit a response with respectto the connection request by disregarding the connection request.

Advertising Procedure

The advertising device performs an advertising procedure to performundirected broadcast to devices within a region.

Here, the undirected broadcast is advertising toward all the devices,rather than broadcast toward a specific device, and all the devices mayscan advertising to make an supplemental information request or aconnection request.

In contrast, directed advertising may make an supplemental informationrequest or a connection request by scanning advertising for only adevice designated as a reception device.

The advertising procedure is used to establish a Bluetooth connectionwith an initiating device nearby.

Or, the advertising procedure may be used to provide periodicalbroadcast of user data to scanning devices performing listening in anadvertising channel.

In the advertising procedure, all the advertisements (or advertisingevents) are broadcast through an advertisement physical channel.

The advertising devices may receive scan requests from listening devicesperforming listening to obtain additional user data from advertisingdevices. The advertising devices transmit responses with respect to thescan requests to the devices which have transmitted the scan requests,through the same advertising physical channels as the advertisingphysical channels in which the scan requests have been received.

Broadcast user data sent as part of advertising packets are dynamicdata, while the scan response data is generally static data.

The advertisement device may receive a connection request from aninitiating device on an advertising (broadcast) physical channel. If theadvertising device has used a connectable advertising event and theinitiating device has not been filtered according to the devicefiltering procedure, the advertising device may stop advertising andenter a connected mode. The advertising device may start advertisingafter the connected mode.

Scanning Procedure

A device performing scanning, that is, a scanning device performs ascanning procedure to listen to undirected broadcasting of user datafrom advertising devices using an advertising physical channel.

The scanning device transmits a scan request to an advertising devicethrough an advertising physical channel in order to request additionaldata from the advertising device. The advertising device transmits ascan response as a response with respect to the scan request, byincluding additional user data which has requested by the scanningdevice through an advertising physical channel.

The scanning procedure may be used while being connected to other BLEdevice in the BLE piconet.

If the scanning device is in an initiator mode in which the scanningdevice may receive an advertising event and initiates a connectionrequest. The scanning device may transmit a connection request to theadvertising device through the advertising physical channel to start aBluetooth connection with the advertising device.

When the scanning device transmits a connection request to theadvertising device, the scanning device stops the initiator modescanning for additional broadcast and enters the connected mode.

Discovering Procedure

Devices available for Bluetooth communication (hereinafter, referred toas “Bluetooth devices”) perform an advertising procedure and a scanningprocedure in order to discover devices located nearby or in order to bediscovered by other devices within a given area.

The discovering procedure is performed asymmetrically. A Bluetoothdevice intending to discover other device nearby is termed a discoveringdevice, and listens to discover devices advertising an advertising eventthat may be scanned. A Bluetooth device which may be discovered by otherdevice and available to be used is termed a discoverable device andpositively broadcasts an advertising event such that it may be scannedby other device through an advertising (broadcast) physical channel.

Both the discovering device and the discoverable device may have alreadybeen connected with other Bluetooth devices in a piconet.

Connecting Procedure

A connecting procedure is asymmetrical, and requests that, while aspecific Bluetooth device is performing an advertising procedure,another Bluetooth device should perform a scanning procedure.

That is, an advertising procedure may be aimed, and as a result, onlyone device may response to the advertising. After a connectableadvertising event is received from an advertising device, a connectingrequest may be transmitted to the advertising device through anadvertising (broadcast) physical channel to initiate connection.

Hereinafter, operational states, that is, an advertising state, ascanning state, an initiating state, and a connection state, in the BLEtechnology will be briefly described.

Advertising State

A link layer (LL) enters an advertising state according to aninstruction from a host (stack). In a case in which the LL is in theadvertising state, the LL transmits an advertising packet data unit(PDU) in advertising events.

Each of the advertising events include at least one advertising PDU, andthe advertising PDU is transmitted through an advertising channel indexin use. After the advertising PDU is transmitted through an advertisingchannel index in use, the advertising event may be terminated, or in acase in which the advertising device may need to secure a space forperforming other function, the advertising event may be terminatedearlier.

Scanning State

The LL enters the scanning state according to an instruction from thehost (stack). In the scanning state, the LL listens to advertisingchannel indices.

The scanning state includes two types: passive scanning and activescanning. Each of the scanning types is determined by the host.

Time for performing scanning or an advertising channel index are notdefined.

During the scanning state, the LL listens to an advertising channelindex in a scan window duration. A scan interval is defined as aninterval between start points of two continuous scan windows.

When there is no collision in scheduling, the LL should listen in orderto complete all the scan intervals of the scan window as instructed bythe host. In each scan window, the LL should scan other advertisingchannel index. The LL uses every available advertising channel index.

In the passive scanning, the LL only receives packets and cannottransmit any packet.

In the active scanning, the LL performs listening in order to be reliedon an advertising PDU type for requesting advertising PDUs andadvertising device-related supplemental information from the advertisingdevice.

Initiating State

The LL enters the initiating state according to an instruction from thehost (stack).

When the LL is in the initiating state, the LL performs listening onadvertising channel indices.

During the initiating state, the LL listens to an advertising channelindex during the scan window interval.

Connection State

When the device performing a connection state, that is, when theinitiating device transmits a CONNECT_REQ_PDU to the advertising deviceor when the advertising device receives a CONNECT_REQ_PDU from theinitiating device, the LL enters a connection state.

It is considered that a connection is generated after the LL enters theconnection state. However, it is not necessary to consider that theconnection should be established at a point in time at which the LLenters the connection state. The only difference between a newlygenerated connection and an already established connection is a LLconnection supervision timeout value.

When two devices are connected, the two devices play different roles.

An LL serving as a master is termed a master, and an LL serving as aslave is termed a slave. The master adjusts a timing of a connectingevent, and the connecting event refers to a point in time at which themaster and the slave are synchronized.

Hereinafter, packets defined in an Bluetooth interface will be brieflydescribed. BLE devices use packets defined as follows.

Packet Format

The LL has only one packet format used for both an advertising channelpacket and a data channel packet.

Each packet includes four fields of a preamble, an access address, aPDU, and a CRC.

When one packet is transmitted in an advertising physical channel, thePDU may be an advertising channel PDU, and when one packet istransmitted in a data physical channel, the PDU may be a data channelPDU.

Advertising Channel PDU

An advertising channel PDU has a 16-bit header and payload havingvarious sizes.

A PDU type field of the advertising channel PDU included in the heaterindicates PDU types defined in Table 3 below.

TABLE 3 PDU Type Packet Name 0000 ADV_IND 0001 ADV_DIRECT_IND 0010ADV_NONCONN_IND 0011 SCAN_REQ 0100 SCAN_RSP 0101 CONNECT_REQ 0110ADV_SCAN_IND 0111-1111 Reserved

Advertising PDU

The following advertising channel PDU types are termed advertising PDUsand used in a specific event.

-   -   ADV_IND: Connectable undirected advertising event    -   ADV_DIRECT_IND: Connectable directed advertising event    -   ADV_NONCONN_IND: Unconnectable undirected advertising event    -   ADV_SCAN_IND: Scannable undirected advertising event

The PDUs are transmitted from the LL in an advertising state, andreceived by the LL in a scanning state or in an initiating state.

Scanning PDU

The following advertising channel DPU types are termed scanning PDUs andare used in a state described hereinafter.

SCAN REQ: Transmitted by the LL in a scanning state and received by theLL in an advertising state.

SCAN RSP: Transmitted by the LL in the advertising state and received bythe LL in the scanning state.

Initiating PDU

The following advertising channel PDU type is termed an initiating PDU.

CONNECT_REQ: Transmitted by the LL in the initiating state and receivedby the LL in the advertising state.

Data Channel PDU

The data channel PDU may include a message integrity check (MIC) fieldhaving a 16-bit header and payload having various sizes.

The procedures, states, and packet formats in the BLE technologydiscussed above may be applied to perform the methods proposed in thepresent disclosure.

Referring to FIG. 4 a , The load (455) may correspond to a battery. Thebattery may store energy by using the power that is being outputted fromthe power pick-up unit (210). Meanwhile, the battery is not mandatorilyrequired to be included in the mobile device (450). For example, thebattery may be provided as a detachable external feature. As anotherexample, the wireless power receiver may include an operating means thatmay execute diverse functions of the electronic device instead of thebattery.

As shown in the drawing, although the mobile device (450) is illustratedto be included in the wireless power receiver (200) and the base station(400) is illustrated to be included in the wireless power transmitter(100), in a broader meaning, the wireless power receiver (200) may beidentified (or regarded) as the mobile device (450), and the wirelesspower transmitter (100) may be identified (or regarded) as the basestation (400).

When the communication/control circuit 120 and the communication/controlcircuit 220 include Bluetooth or Bluetooth LE as an OB communicationmodule or a short-range communication module in addition to the IBcommunication module, the wireless power transmitter 100 including thecommunication/control circuit 120 and the wireless power receiver 200including the communication/control circuit 220 may be represented by asimplified block diagram as shown in FIG. 4C.

FIG. 4C is a block diagram illustrating a wireless power transfer systemusing BLE communication according to an example.

Referring to FIG. 4C, the wireless power transmitter 100 includes apower conversion circuit 110 and a communication/control circuit 120.The communication/control circuit 120 includes an in-band communicationmodule 121 and a BLE communication module 122.

Meanwhile, the wireless power receiver 200 includes a power pickupcircuit 210 and a communication/control circuit 220. Thecommunication/control circuit 220 includes an in-band communicationmodule 221 and a BLE communication module 222.

In one aspect, the BLE communication modules 122 and 222 perform thearchitecture and operation according to FIG. 4B. For example, the BLEcommunication modules 122 and 222 may be used to establish a connectionbetween the wireless power transmitter 100 and the wireless powerreceiver 200 and exchange control information and packets necessary forwireless power transfer.

In another aspect, the communication/control circuit 120 may beconfigured to operate a profile for wireless charging. Here, the profilefor wireless charging may be GATT using BLE transmission.

Referring to FIG. 4D, the communication/control circuits 120 and 220respectively include only in-band communication modules 121 and 221, andthe BLE communication modules 122 and 222 may be provided to beseparated from the communication/control circuits 120 and 220.

Hereinafter, the coil or coil unit includes a coil and at least onedevice being approximate to the coil, and the coil or coil unit may alsobe referred to as a coil assembly, a coil cell, or a cell.

FIG. 5 is a state transition diagram for describing a wireless powertransfer procedure.

Referring to FIG. 5 , the power transfer (or transfer) from the wirelesspower transmitter to the wireless power receiver according to anexemplary embodiment of the present disclosure may be broadly dividedinto a selection phase (510), a ping phase (520), an identification andconfiguration phase (530), a negotiation phase (540), a calibrationphase (550), a power transfer phase (560), and a renegotiation phase(570).

If a specific error or a specific event is detected when the powertransfer is initiated or while maintaining the power transfer, theselection phase (510) may include a shifting phase (or step)—referencenumerals S502, S504, S508, S510, and S512. Herein, the specific error orspecific event will be specified in the following description.Additionally, during the selection phase (510), the wireless powertransmitter may monitor whether or not an object exists on an interfacesurface. If the wireless power transmitter detects that an object isplaced on the interface surface, the process step may be shifted to theping phase (520). During the selection phase (510), the wireless powertransmitter may transmit an analog ping having a power signal(or apulse) corresponding to an extremely short duration, and may detectwhether or not an object exists within an active area of the interfacesurface based on a current change in the transmitting coil or theprimary coil.

In case an object is sensed (or detected) in the selection phase (510),the wireless power transmitter may measure a quality factor of awireless power resonance circuit (e.g., power transfer coil and/orresonance capacitor). According to the exemplary embodiment of thepresent disclosure, during the selection phase (510), the wireless powertransmitter may measure the quality factor in order to determine whetheror not a foreign object exists in the charging area along with thewireless power receiver. In the coil that is provided in the wirelesspower transmitter, inductance and/or components of the series resistancemay be reduced due to a change in the environment, and, due to suchdecrease, a value of the quality factor may also be decreased. In orderto determine the presence or absence of a foreign object by using themeasured quality factor value, the wireless power transmitter mayreceive from the wireless power receiver a reference quality factorvalue, which is measured in advance in a state where no foreign objectis placed within the charging area. The wireless power transmitter maydetermine the presence or absence of a foreign object by comparing themeasured quality factor value with the reference quality factor value,which is received during the negotiation phase (540). However, in caseof a wireless power receiver having a low reference quality factorvalue—e.g., depending upon its type, purpose, characteristics, and soon, the wireless power receiver may have a low reference quality factorvalue—in case a foreign object exists, since the difference between thereference quality factor value and the measured quality factor value issmall (or insignificant), a problem may occur in that the presence ofthe foreign object cannot be easily determined. Accordingly, in thiscase, other determination factors should be further considered, or thepresent or absence of a foreign object should be determined by usinganother method.

According to another exemplary embodiment of the present disclosure, incase an object is sensed (or detected) in the selection phase (510), inorder to determine whether or not a foreign object exists in thecharging area along with the wireless power receiver, the wireless powertransmitter may measure the quality factor value within a specificfrequency area (e.g., operation frequency area). In the coil that isprovided in the wireless power transmitter, inductance and/or componentsof the series resistance may be reduced due to a change in theenvironment, and, due to such decrease, the resonance frequency of thecoil of the wireless power transmitter may be changed (or shifted). Morespecifically, a quality factor peak frequency that corresponds to afrequency in which a maximum quality factor value is measured within theoperation frequency band may be moved (or shifted).

In the ping phase (520), if the wireless power transmitter detects thepresence of an object, the transmitter activates (or Wakes up) areceiver and transmits a digital ping for identifying whether or not thedetected object corresponds to the wireless power receiver. During theping phase (520), if the wireless power transmitter fails to receive aresponse signal for the digital ping—e.g., a signal intensitypacket—from the receiver, the process may be shifted back to theselection phase (510). Additionally, in the ping phase (520), if thewireless power transmitter receives a signal indicating the completionof the power transfer—e.g., charging complete packet—from the receiver,the process may be shifted back to the selection phase (510).

If the ping phase (520) is completed, the wireless power transmitter mayshift to the identification and configuration phase (530) foridentifying the receiver and for collecting configuration and statusinformation.

In the identification and configuration phase (530), if the wirelesspower transmitter receives an unwanted packet (i.e., unexpected packet),or if the wireless power transmitter fails to receive a packet during apredetermined period of time (i.e., out of time), or if a packettransmission error occurs (i.e., transmission error), or if a powertransfer contract is not configured (i.e., no power transfer contract),the wireless power transmitter may shift to the selection phase (510).

The wireless power transmitter may confirm (or verify) whether or notits entry to the negotiation phase (540) is needed based on aNegotiation field value of the configuration packet, which is receivedduring the identification and configuration phase (530). Based on theverified result, in case a negotiation is needed, the wireless powertransmitter enters the negotiation phase (540) and may then perform apredetermined FOD detection procedure. Conversely, in case a negotiationis not needed, the wireless power transmitter may immediately enter thepower transfer phase (560).

In the negotiation phase (540), the wireless power transmitter mayreceive a Foreign Object Detection (FOD) status packet that includes areference quality factor value. Or, the wireless power transmitter mayreceive an FOD status packet that includes a reference peak frequencyvalue. Alternatively, the wireless power transmitter may receive astatus packet that includes a reference quality factor value and areference peak frequency value. At this point, the wireless powertransmitter may determine a quality coefficient threshold value for FOdetection based on the reference quality factor value. The wirelesspower transmitter may determine a peak frequency threshold value for FOdetection based on the reference peak frequency value.

The wireless power transmitter may detect the presence or absence of anFO in the charging area by using the determined quality coefficientthreshold value for FO detection and the currently measured qualityfactor value (i.e., the quality factor value that was measured beforethe ping phase), and, then, the wireless power transmitter may controlthe transmitted power in accordance with the FO detection result. Forexample, in case the FO is detected, the power transfer may be stopped.However, the present disclosure will not be limited only to this.

The wireless power transmitter may detect the presence or absence of anFO in the charging area by using the determined peak frequency thresholdvalue for FO detection and the currently measured peak frequency value(i.e., the peak frequency value that was measured before the pingphase), and, then, the wireless power transmitter may control thetransmitted power in accordance with the FO detection result. Forexample, in case the FO is detected, the power transfer may be stopped.However, the present disclosure will not be limited only to this.

In case the FO is detected, the wireless power transmitter may return tothe selection phase (510). Conversely, in case the FO is not detected,the wireless power transmitter may proceed to the calibration phase(550) and may, then, enter the power transfer phase (560). Morespecifically, in case the FO is not detected, the wireless powertransmitter may determine the intensity of the received power that isreceived by the receiving end during the calibration phase (550) and maymeasure power loss in the receiving end and the transmitting end inorder to determine the intensity of the power that is transmitted fromthe transmitting end. In other words, during the calibration phase(550), the wireless power transmitter may estimate the power loss basedon a difference between the transmitted power of the transmitting endand the received power of the receiving end. The wireless powertransmitter according to the exemplary embodiment of the presentdisclosure may calibrate the threshold value for the FOD detection byapplying the estimated power loss.

In the power transfer phase (560), in case the wireless powertransmitter receives an unwanted packet (i.e., unexpected packet), or incase the wireless power transmitter fails to receive a packet during apredetermined period of time (i.e., time-out), or in case a violation ofa predetermined power transfer contract occurs (i.e., power transfercontract violation), or in case charging is completed, the wirelesspower transmitter may shift to the selection phase (510).

Additionally, in the power transfer phase (560), in case the wirelesspower transmitter is required to reconfigure the power transfer contractin accordance with a status change in the wireless power transmitter,the wireless power transmitter may shift to the renegotiation phase(570). At this point, if the renegotiation is successfully completed,the wireless power transmitter may return to the power transfer phase(560).

In this embodiment, the calibration step 550 and the power transferphase 560 are divided into separate steps, but the calibration step 550may be integrated into the power transfer phase 560. In this case,operations in the calibration step 550 may be performed in the powertransfer phase 560.

The above-described power transfer contract may be configured based onthe status and characteristic information of the wireless powertransmitter and receiver. For example, the wireless power transmitterstatus information may include information on a maximum amount oftransmittable power, information on a maximum number of receivers thatmay be accommodated, and so on. And, the receiver status information mayinclude information on the required power, and so on.

FIG. 6 shows a power control method according to an exemplary embodimentof the present disclosure.

As shown in FIG. 6 , in the power transfer phase (560), by alternatingthe power transfer and/or reception and communication, the wirelesspower transmitter (100) and the wireless power receiver (200) maycontrol the amount (or size) of the power that is being transferred. Thewireless power transmitter and the wireless power receiver operate at aspecific control point. The control point indicates a combination of thevoltage and the electric current that are provided from the output ofthe wireless power receiver, when the power transfer is performed.

More specifically, the wireless power receiver selects a desired controlpoint, a desired output current/voltage, a temperature at a specificlocation of the mobile device, and so on, and additionally determines anactual control point at which the receiver is currently operating. Thewireless power receiver calculates a control error value by using thedesired control point and the actual control point, and, then, thewireless power receiver may transmit the calculated control error valueto the wireless power transmitter as a control error packet.

Also, the wireless power transmitter may configure/control a newoperating point—amplitude, frequency, and duty cycle—by using thereceived control error packet, so as to control the power transfer.Therefore, the control error packet may be transmitted/received at aconstant time interval during the power transfer phase, and, accordingto the exemplary embodiment, in case the wireless power receiverattempts to reduce the electric current of the wireless powertransmitter, the wireless power receiver may transmit the control errorpacket by setting the control error value to a negative number. And, incase the wireless power receiver intends to increase the electriccurrent of the wireless power transmitter, the wireless power receivertransmit the control error packet by setting the control error value toa positive number. During the induction mode, by transmitting thecontrol error packet to the wireless power transmitter as describedabove, the wireless power receiver may control the power transfer.

In the resonance mode, which will hereinafter be described in detail,the device may be operated by using a method that is different from theinduction mode. In the resonance mode, one wireless power transmittershould be capable of serving a plurality of wireless power receivers atthe same time. However, in case of controlling the power transfer justas in the induction mode, since the power that is being transferred iscontrolled by a communication that is established with one wirelesspower receiver, it may be difficult to control the power transfer ofadditional wireless power receivers. Therefore, in the resonance modeaccording to the present disclosure, a method of controlling the amountof power that is being received by having the wireless power transmittercommonly transfer (or transmit) the basic power and by having thewireless power receiver control its own resonance frequency.Nevertheless, even during the operation of the resonance mode, themethod described above in FIG. 6 will not be completely excluded. And,additional control of the transmitted power may be performed by usingthe method of FIG. 6 .

FIG. 7 is a block diagram of a wireless power transmitter according toanother exemplary embodiment of the present disclosure. This may belongto a wireless power transfer system that is being operated in themagnetic resonance mode or the shared mode. The shared mode may refer toa mode performing a several-for-one (or one-to-many) communication andcharging between the wireless power transmitter and the wireless powerreceiver. The shared mode may be implemented as a magnetic inductionmethod or a resonance method.

Referring to FIG. 7 , the wireless power transmitter (700) may includeat least one of a cover (720) covering a coil assembly, a power adapter(730) supplying power to the power transmitter (740), a powertransmitter (740) transmitting wireless power, and a user interface(750) providing information related to power transfer processing andother related information. Most particularly, the user interface (750)may be optionally included or may be included as another user interface(750) of the wireless power transmitter (700).

The power transmitter (740) may include at least one of a coil assembly(760), an impedance matching circuit (770), an inverter (780), acommunication unit (790), and a control unit (710).

The coil assembly (760) includes at least one primary coil generating amagnetic field. And, the coil assembly (760) may also be referred to asa coil cell.

The impedance matching circuit (770) may provide impedance matchingbetween the inverter and the primary coil(s). The impedance matchingcircuit (770) may generate resonance from a suitable frequency thatboosts the electric current of the primary coil(s). In a multi-coilpower transmitter (740), the impedance matching circuit may additionallyinclude a multiplex that routes signals from the inverter to a subset ofthe primary coils. The impedance matching circuit may also be referredto as a tank circuit.

The impedance matching circuit (770) may include a capacitor, aninductor, and a switching device that switches the connection betweenthe capacitor and the inductor. The impedance matching may be performedby detecting a reflective wave of the wireless power that is beingtransferred (or transmitted) through the coil assembly (760) and byswitching the switching device based on the detected reflective wave,thereby adjusting the connection status of the capacitor or the inductoror adjusting the capacitance of the capacitor or adjusting theinductance of the inductor. In some cases, the impedance matching may becarried out even though the impedance matching circuit (770) is omitted.This specification also includes an exemplary embodiment of the wirelesspower transmitter (700), wherein the impedance matching circuit (770) isomitted.

The inverter (780) may convert a DC input to an AC signal. The inverter(780) may be operated as a half-bridge inverter or a full-bridgeinverter in order to generate a pulse wave and a duty cycle of anadjustable frequency. Additionally, the inverter may include a pluralityof stages in order to adjust input voltage levels.

The communication unit (790) may perform communication with the powerreceiver. The power receiver performs load modulation in order tocommunicate requests and information corresponding to the powertransmitter. Therefore, the power transmitter (740) may use thecommunication unit (790) so as to monitor the amplitude and/or phase ofthe electric current and/or voltage of the primary coil in order todemodulate the data being transmitted from the power receiver.

Additionally, the power transmitter (740) may control the output powerto that the data may be transferred through the communication unit (790)by using a Frequency Shift Keying (FSK) method, and so on.

The control unit (710) may control communication and power transfer (ordelivery) of the power transmitter (740). The control unit (710) maycontrol the power transfer by adjusting the above-described operatingpoint. The operating point may be determined by, for example, at leastany one of the operation frequency, the duty cycle, and the inputvoltage.

The communication unit (790) and the control unit (710) may each beprovided as a separate unit/device/chipset or may be collectivelyprovided as one unit/device/chipset.

FIG. 8 shows a wireless power receiver according to another exemplaryembodiment of the present disclosure. This may belong to a wirelesspower transfer system that is being operated in the magnetic resonancemode or the shared mode.

Referring to FIG. 8 , the wireless power receiver (800) may include atleast one of a user interface (820) providing information related topower transfer processing and other related information, a powerreceiver (830) receiving wireless power, a load circuit (840), and abase (850) supporting and covering the coil assembly. Most particularly,the user interface (820) may be optionally included or may be includedas another user interface (820) of the wireless power receiver (800).

The power receiver (830) may include at least one of a power converter(860), an impedance matching circuit (870), a coil assembly (880), acommunication unit (890), and a control unit (810).

The power converter (860) may convert the AC power that is received fromthe secondary coil to a voltage and electric current that are suitablefor the load circuit. According to an exemplary embodiment, the powerconverter (860) may include a rectifier. The rectifier may rectify thereceived wireless power and may convert the power from an alternatingcurrent (AC) to a direct current (DC). The rectifier may convert thealternating current to the direct current by using a diode or atransistor, and, then, the rectifier may smooth the converted current byusing the capacitor and resistance. Herein, a full-wave rectifier, ahalf-wave rectifier, a voltage multiplier, and so on, that areimplemented as a bridge circuit may be used as the rectifier.Additionally, the power converter may adapt a reflected impedance of thepower receiver.

The impedance matching circuit (870) may provide impedance matchingbetween a combination of the power converter (860) and the load circuit(840) and the secondary coil. According to an exemplary embodiment, theimpedance matching circuit may generate a resonance of approximately 100kHz, which may reinforce the power transfer. The impedance matchingcircuit (870) may include a capacitor, an inductor, and a switchingdevice that switches the combination of the capacitor and the inductor.The impedance matching may be performed by controlling the switchingdevice of the circuit that configured the impedance matching circuit(870) based on the voltage value, electric current value, power value,frequency value, and so on, of the wireless power that is beingreceived. In some cases, the impedance matching may be carried out eventhough the impedance matching circuit (870) is omitted. Thisspecification also includes an exemplary embodiment of the wirelesspower receiver (200), wherein the impedance matching circuit (870) isomitted.

The coil assembly (880) includes at least one secondary coil, and,optionally, the coil assembly (880) may further include an elementshielding the metallic part of the receiver from the magnetic field.

The communication unit (890) may perform load modulation in order tocommunicate requests and other information to the power transmitter.

For this, the power receiver (830) may perform switching of theresistance or capacitor so as to change the reflected impedance.

The control unit (810) may control the received power. For this, thecontrol unit (810) may determine/calculate a difference between anactual operating point and a target operating point of the powerreceiver (830). Thereafter, by performing a request for adjusting thereflected impedance of the power transmitter and/or for adjusting anoperating point of the power transmitter, the difference between theactual operating point and the target operating point may beadjusted/reduced. In case of minimizing this difference, an optimalpower reception may be performed.

The communication unit (890) and the control unit (810) may each beprovided as a separate device/chipset or may be collectively provided asone device/chipset.

FIG. 9 shows a communication frame structure according to an exemplaryembodiment of the present disclosure. This may correspond to acommunication frame structure in a shared mode.

Referring to FIG. 9 , in the shared mode, different forms of frames maybe used along with one another. For example, in the shared mode, aslotted frame having a plurality of slots, as shown in (A), and a freeformat frame that does not have a specified format, as shown in (B), maybe used. More specifically, the slotted frame corresponds to a frame fortransmitting short data packets from the wireless power receiver (200)to the wireless power transmitter (100). And, since the free formatframe is not configured of a plurality of slots, the free format framemay correspond to a frame that is capable of performing transmission oflong data packets.

Meanwhile, the slotted frame and the free format frame may be referredto other diverse terms by anyone skilled in the art. For example, theslotted frame may be alternatively referred to as a channel frame, andthe free format frame may be alternatively referred to as a messageframe.

More specifically, the slotted frame may include a sync patternindicating the starting point (or beginning) of a slot, a measurementslot, nine slots, and additional sync patterns each having the same timeinterval that precedes each of the nine slots.

Herein, the additional sync pattern corresponds to a sync pattern thatis different from the sync pattern that indicates the starting point ofthe above-described frame. More specifically, the additional syncpattern does not indicate the starting point of the frame but mayindicate information related to the neighboring (or adjacent) slots(i.e., two consecutive slots positioned on both sides of the syncpattern).

Among the nine slots, each sync pattern may be positioned between twoconsecutive slots. In this case, the sync pattern may provideinformation related to the two consecutive slots.

Additionally, the nine slots and the sync patterns being provided beforeeach of the nine slots may have the same time interval. For example, thenine slots may have a time interval of 50 ms. And, the nine syncpatterns may have a time length of 50 ms.

Meanwhile, the free format frame, as shown in (B) may not have aspecific format apart from the sync pattern indicating the startingpoint of the frame and the measurement slot. More specifically, the freeformat frame is configured to perform a function that is different fromthat of the slotted frame. For example, the free format frame may beused to perform a function of performing communication of long datapackets (e.g., additional owner information packets) between thewireless power transmitter and the wireless power receiver, or, in caseof a wireless power transmitter being configured of multiple coils, toperform a function of selecting any one of the coils.

Hereinafter, a sync pattern that is included in each frame will bedescribed in more detail with reference to the accompanying drawings.

FIG. 10 is a structure of a sync pattern according to an exemplaryembodiment of the present disclosure.

Referring to FIG. 10 , the sync pattern may be configured of a preamble,a start bit, a response field, a type field, an info field, and a paritybit. In FIG. 10 , the start bit is illustrated as ZERO.

More specifically, the preamble is configured of consecutive bits, andall of the bits may be set to 0. In other words, the preamble maycorrespond to bits for matching a time length of the sync pattern.

The number of bits configuring the preamble may be subordinate to theoperation frequency so that the length of the sync pattern may be mostapproximate to 50 ms but within a range that does not exceed 50 ms. Forexample, in case the operation frequency corresponds to 100 kHz, thesync pattern may be configured of two preamble bits, and, in case theoperation frequency corresponds to 105 kHz, the sync pattern may beconfigured of three preamble bits.

The start bit may correspond to a bit that follows the preamble, and thestart bit may indicate ZERO. The ZERO may correspond to a bit thatindicates a type of the sync pattern. Herein, the type of sync patternsmay include a frame sync including information that is related to aframe, and a slot sync including information of the slot. Morespecifically, the sync pattern may be positioned between consecutiveframes and may correspond to a frame sync that indicate a start of theframe, or the sync pattern may be positioned between consecutive slotsamong a plurality of slots configuring the frame and may correspond to async slot including information related to the consecutive slots.

For example, in case the ZERO is equal to 0, this may indicate that thecorresponding slot is a slot sync that is positioned in-between slots.And, in case the ZERO is equal to 1, this may indicate that thecorresponding sync pattern is a frame sync being located in-betweenframes.

A parity bit corresponds to a last bit of the sync pattern, and theparity bit may indicate information on a number of bits configuring thedata fields (i.e., the response field, the type field, and the infofield) that are included in the sync pattern. For example, in case thenumber of bits configuring the data fields of the sync patterncorresponds to an even number, the parity bit may be set to when, and,otherwise (i.e., in case the number of bits corresponds to an oddnumber), the parity bit may be set to 0.

The response field may include response information of the wirelesspower transmitter for its communication with the wireless power receiverwithin a slot prior to the sync pattern. For example, in case acommunication between the wireless power transmitter and the wirelesspower receiver is not detected, the response field may have a value of‘00’. Additionally, if a communication error is detected in thecommunication between the wireless power transmitter and the wirelesspower receiver, the response field may have a value of ‘01’. Thecommunication error corresponds to a case where two or more wirelesspower receivers attempt to access one slot, thereby causing collision tooccur between the two or more wireless power receivers.

Additionally, the response field may include information indicatingwhether or not the data packet has been accurately received from thewireless power receiver. More specifically, in case the wireless powertransmitter has denied the data packet, the response field may have avalue of “10” (10—not acknowledge (NAK)). And, in case the wirelesspower transmitter has confirmed the data packet, the response field mayhave a value of “11” (11—acknowledge (ACK)).

The type field may indicate the type of the sync pattern. Morespecifically, in case the sync pattern corresponds to a first syncpattern of the frame (i.e., as the first sync pattern, in case the syncpattern is positioned before the measurement slot), the type field mayhave a value of ‘1’, which indicates a frame sync.

Additionally, in a slotted frame, in case the sync pattern does notcorrespond to the first sync pattern of the frame, the type field mayhave a value of ‘0’, which indicates a slot sync.

Moreover, the information field may determine the meaning of its valuein accordance with the sync pattern type, which is indicated in the typefield. For example, in case the type field is equal to 1 (i.e., in casethe sync pattern type indicates a frame sync), the meaning of theinformation field may indicate the frame type. More specifically, theinformation field may indicate whether the current frame corresponds toa slotted frame or a free-format frame. For example, in case theinformation field is given a value of ‘00’, this indicates that thecurrent frame corresponds to a slotted frame. And, in case theinformation field is given a value of ‘01’, this indicates that thecurrent frame corresponds to a free-format frame.

Conversely, in case the type field is equal to 0 (i.e., in case the syncpattern type indicates a slot sync), the information field may indicatea state of a next slot, which is positioned after the sync pattern. Morespecifically, in case the next slot corresponds to a slot that isallocated (or assigned) to a specific wireless power receiver, theinformation field is given a value of ‘00’. In case the next slotcorresponds to a slot that is locked, so as to be temporarily used bythe specific wireless power receiver, the information field is given avalue of ‘01’. Alternatively, in case the next slot corresponds to aslot that may be freely used by a random wireless power receiver, theinformation field is given a value of ‘10’.

FIG. 11 shows operation statuses of a wireless power transmitter and awireless power receiver in a shared mode according to an exemplaryembodiment of the present disclosure.

Referring to FIG. 11 , the wireless power receiver operating in theshared mode may be operated in any one of a selection phase (1100), anintroduction phase (1110), a configuration phase (1120), a negotiationphase (1130), and a power transfer phase (1140).

Firstly, the wireless power transmitter according to the exemplaryembodiment of the present disclosure may transmit a wireless powersignal in order to detect the wireless power receiver. Morespecifically, a process of detecting a wireless power receiver by usingthe wireless power signal may be referred to as an Analog ping.

Meanwhile, the wireless power receiver that has received the wirelesspower signal may enter the selection phase (1100). As described above,the wireless power receiver that has entered the selection phase (1100)may detect the presence or absence of an FSK signal within the wirelesspower signal.

In other words, the wireless power receiver may perform communication byusing any one of an exclusive mode and a shared mode in accordance withthe presence or absence of the FSK signal.

More specifically, in case the FSK signal is included in the wirelesspower signal, the wireless power receiver may operate in the sharedmode, and, otherwise, the wireless power receiver may operate in theexclusive mode.

In case the wireless power receiver operates in the shared mode, thewireless power receiver may enter the introduction phase (1110). In theintroduction phase (1110), the wireless power receiver may transmit acontrol information (CI) packet to the wireless power transmitter inorder to transmit the control information packet during theconfiguration phase, the negotiation phase, and the power transferphase. The control information packet may have a header and informationrelated to control. For example, in the control information packet, theheader may correspond to 0X53.

In the introduction phase (1110), the wireless power receiver performsan attempt to request a free slot for transmitting the controlinformation (CI) packet during the following configuration phase,negotiation phase, and power transfer phase. At this point, the wirelesspower receiver selects a free slot and transmits an initial CI packet.If the wireless power transmitter transmits an ACK as a response to thecorresponding CI packet, the wireless power receiver enters theconfiguration phase. If the wireless power transmitter transmits a NAKas a response to the corresponding CI packet, this indicates thatanother wireless power receiver is performing communication through theconfiguration and negotiation phase. In this case, the wireless powerreceiver re-attempts to perform a request for a free slot.

If the wireless power receiver receives an ACK as a response to the CIpacket, the wireless power receiver may determine the position of aprivate slot within the frame by counting the remaining sync slots up tothe initial frame sync. In all of the subsequent slot-based frames, thewireless power receiver transmits the CI packet through thecorresponding slot.

If the wireless power transmitter authorizes the entry of the wirelesspower receiver to the configuration phase, the wireless powertransmitter provides a locked slot series for the exclusive usage of thewireless power receiver. This may ensure the wireless power receiver toproceed to the configuration phase without any collision.

The wireless power receiver transmits sequences of data packets, such astwo identification data packets (IDHI and IDLO), by using the lockedslots. When this phase is completed, the wireless power receiver entersthe negotiation phase. During the negotiation state, the wireless powertransmitter continues to provide the locked slots for the exclusiveusage of the wireless power receiver. This may ensure the wireless powerreceiver to proceed to the negotiation phase without any collision.

The wireless power receiver transmits one or more negotiation datapackets by using the corresponding locked slot, and the transmittednegotiation data packet(s) may be mixed with the private data packets.Eventually, the corresponding sequence is ended (or completed) alongwith a specific request (SRQ) packet. When the corresponding sequence iscompleted, the wireless power receiver enters the power transfer phase,and the wireless power transmitter stops the provision of the lockedslots.

In the power transfer phase, the wireless power receiver performs thetransmission of a CI packet by using the allocated slots and thenreceives the power. The wireless power receiver may include a regulatorcircuit. The regulator circuit may be included in acommunication/control unit. The wireless power receiver mayself-regulate a reflected impedance of the wireless power receiverthrough the regulator circuit. In other words, the wireless powerreceiver may adjust the impedance that is being reflected for an amountof power that is requested by an external load. This may prevent anexcessive reception of power and overheating.

In the shared mode, (depending upon the operation mode) since thewireless power transmitter may not perform the adjustment of power as aresponse to the received CI packet, in this case, control may be neededin order to prevent an overvoltage state.

A wireless power transmission system may include a message exchangefunction of an application layer for supporting an extension to variousapplication fields. Based on the function, authentication relatedinformation or other information on an application level of a device maybe transmitted and received between a wireless power transmission deviceand a wireless power reception device. For the exchange of higher layermessages between a wireless power transmission device and a wirelesspower reception device, a separate hierarchical architecture for datatransmission is required, and an efficient managing and operating methodis required for the hierarchical architecture.

FIG. 12 shows an application-level data stream between a wireless powertransmitter and a receiver according to an example.

Referring to FIG. 12 , a data stream may include an auxiliary datacontrol (ADC) data packet and/or an auxiliary data transport (ADT) datapacket.

The ADC data packet is used to open a data stream. The ADC data packetmay indicate the type of a message included in a stream and the numberof data bytes. Meanwhile, the ADT data packet is sequences of dataincluding an actual message. An ADC/end data packet is used to indicatethe end of the stream. For example, the maximum number of data bytes ina data transport stream may be limited to 2047.

ACK or NACK is used to indicate whether the ADC data packet and the ADTdata packet are normally received. Control information necessary forwireless charging such as a control error packet (CE) or DSR may betransmitted between transmission timings of the ADC data packet and theADT data packet.

Using this data stream structure, authentication related information orother application level information may be transmitted and receivedbetween the wireless power transmitter and the wireless power receiver.

FIG. 13 illustrates a hierarchical architecture for transmitting a datastream between a wireless power transmission device and a wireless powerreception device.

Referring to FIG. 13 , a data stream is exchanged between a data streaminitiator and a data stream responder. Both of a wireless powertransmission device and a wireless power reception device may become thedata stream initiator or the data stream responder. For example, in thecase that the data stream initiator is the wireless power receptiondevice, the data stream responder is the wireless power transmissiondevice, and in the case that the data stream initiator is the wirelesspower transmission device, the data stream responder is the wirelesspower reception device.

The data stream initiator generates a message in an application layerlevel (e.g., an authentication related message) and stores it in abuffer managed by an application layer. In addition, the data streaminitiator submits the message stored in the buffer to a transport layerfrom the application layer. The data stream initiator stores the messagein a local buffer managed by the transport layer. A size of the localbuffer of the transport layer may be at least 67 bytes, for example.

The data stream initiator transmits the message to the data streamresponder through a wireless channel by using a data transport stream ofthe transport layer. At this time, the message is transmitted with beingsliced into multiple packets, and this may be called a data transportstream. In the case that an error occurs during the transmission processof data packets, the data stream initiator may retransmit the packet inwhich an error occurs, and in this case, the transport layer of the datastream initiator may perform a feedback for a success or a failure ofthe message transmission for the application layer.

The data stream initiator receives the data transport stream through awireless channel. The received data transport stream is demodulated anddecoded in the reverse process of the process of the data streaminitiator. For example, the data stream responder stores the datatransport stream in the local buffer managed by the transport layer andmerges it, and then forwards it to the application layer. Theapplication layer stores the transferred message in a buffer.

Control of Data Stream

As described above, the wireless power transmission apparatus and thewireless power reception apparatus may exchange data stream during thepower transfer phase. For example, each of the wireless powertransmission apparatus and the wireless power reception apparatus mayopen one data stream. Specifically, when one side opens an outgoing datastream, it may refuse the opening of an incoming data stream until thetransmission of the data stream is completed. This is for easiness of animplementation.

The wireless power reception apparatus operates as a master, and mayrefuse the wireless power transmission apparatus the opening of a newdata stream by not responding to a request for the opening of the datastream of the wireless power transmission apparatus. In contrast, thewireless power transmission apparatus cannot refuse the opening of adata stream because the wireless power reception apparatus is a master.That is, even though the wireless power transmission apparatus does notrespond, the wireless power reception apparatus may continue to transmitthe data stream. This cause to degrade system performance because ithinders the transmission of a data stream that is already opened andtransmitted. Accordingly, there is a need for a protocol through which adata stream can be effectively exchanged.

Accordingly, the present embodiment discloses a wireless powertransmission apparatus and wireless power reception apparatus configuredto simultaneously or selectively open or process an outgoing data streamand an incoming data stream. The wireless power transmission apparatusand wireless power reception apparatus configured to simultaneously openor process an outgoing data stream and an incoming data stream transmitor receive multiple data streams between them.

Hereinafter, multiple data streams may mean simultaneous data streamsand an incoming data stream. Alternatively, the multiple data streamsmay mean a full-duplex data stream.

For example, the wireless power transmission apparatus may support asingle data stream at a time or may support a simultaneous (or multipleoutgoing/incoming) data stream. Furthermore, the wireless powertransmission apparatus may transmit, to the wireless power receptionapparatus, duplex data stream information indicating whether it supportsa single data stream or supports simultaneous data streams. The duplexdata stream information may be included in a capability packet of thewireless power transmission apparatus, and a name thereof may be calleda data stream (DS) bit or a full-duplex bit or simply a duplex bit.

If the wireless power transmission apparatus supports a single datastream, it transmits, to the wireless power reception apparatus, duplexdata stream information indicating that it supports a single datastream, opens a single (outgoing or incoming) data stream at a time, andopens a new (outgoing or incoming) data stream when the transmission ofthe single data stream is terminated.

If the wireless power transmission apparatus supports simultaneous datastreams, it transmits, to the wireless power reception apparatus, duplexdata stream information indicating that it supports the simultaneousdata streams. Furthermore, the wireless power transmission apparatusdetermines whether the wireless power reception apparatus supportssimultaneous data streams. If the wireless power reception apparatussupports the simultaneous data streams, the wireless power transmissionapparatus may open the simultaneous (outgoing and incoming) datastreams. In contrast, if the wireless power reception apparatus supportsa single data stream even though the wireless power transmissionapparatus supports simultaneous data streams, the wireless powertransmission apparatus opens a single (outgoing or incoming) data streamat a time, and opens a new (outgoing or incoming) data stream when thetransmission of the single data stream is terminated.

For another example, the wireless power reception apparatus may supporta single data stream at a time or may support simultaneous (or multipleoutgoing/incoming) data streams. Furthermore, the wireless powerreception apparatus may transmit, to the wireless power receptionapparatus, duplex data stream information indicating whether it supportsa single data stream or supports simultaneous data streams. The duplexdata stream information may be included in a capability packet of thewireless power transmission apparatus, and a name thereof may be calleda data stream (DS) bit or simply a duplex bit.

If the wireless power reception apparatus supports a single data stream,it transmits, to the wireless power transmission apparatus, duplex datastream information indicating that it supports a single data stream,opens a single (outgoing or incoming) data stream at a time, and opens anew (outgoing or incoming) data stream when the transmission of thesingle data stream is terminated.

If the wireless power reception apparatus supports simultaneous datastreams, it transmits, to the wireless power transmission apparatus,duplex data stream information indicating that it supports simultaneousdata streams. Furthermore, the wireless power reception apparatusdetermines whether the wireless power transmission apparatus supportssimultaneous data streams. If the wireless power transmission apparatussupports the simultaneous data streams, the wireless power receptionapparatus may open simultaneous (outgoing and incoming) data streams. Incontrast, even though the wireless power reception apparatus supportsthe simultaneous data streams, if the wireless power transmissionapparatus supports a single data stream, the wireless power receptionapparatus opens a single (outgoing or incoming) data stream at a time,and opens a new (outgoing or incoming) data stream when the transmissionof the single data stream is terminated.

FIG. 14 is a flowchart illustrating a method of transmitting a datastream according to an example.

Referring to FIG. 14 , the wireless power reception apparatus transmits,to the wireless power transmission apparatus, a configuration packetincluding duplex data stream (DS) information (S1400). The duplex datastream information may be information of 1 bit indicating whether thewireless power reception apparatus supports or does not supportsimultaneous data streams (or support a single data stream). Forexample, when the duplex data stream information is 1, it indicates thatthe wireless power reception apparatus supports the simultaneous datastreams. When the duplex data stream information is 0, it indicates thatthe wireless power reception apparatus does not support the simultaneousdata streams. By using one bit in the configuration packet as describedabove, the wireless power reception apparatus may indicate whether afunction capable of simultaneously processing two data streams (orsimultaneous data streams) is present or not.

FIG. 15 is a configuration packet including duplex data streaminformation according to an example.

Referring to FIG. 15 , the configuration packet may include at least oneof a received power scaling factor field, a reserved field, a Prop fieldrelated to personal power control information, an AI field regardingwhether an authentication initiator function is supported, an AR fieldregarding whether an authentication responder function is supported, anOB field whether outband communication is supported, a count field, awindow size field, a window offset field, an Neg field whether anextended protocol is supported, a Pol field indicative of the polarityof FSK modulation, a Depth field indicative of the depth of FSKmodulation, and a duplex data stream(DS) field.

Referring back to FIG. 14 , the wireless power transmission apparatustransmits, to the wireless power reception apparatus, a capabilitypacket including duplex data stream information (S1405). The duplex datastream information is information indicating whether the wireless powertransmission apparatus supports or does not support simultaneous datastreams (or supports a single data stream). For example, when the duplexdata stream information is 1, it indicates that the wireless powertransmission apparatus supports the simultaneous data streams. When theduplex data stream information is 0, it indicates that the wirelesspower transmission apparatus does not support the simultaneous datastreams. By using one bit in the capability packet as described above,the wireless power transmission apparatus may indicate whether afunction capable of simultaneously processing two data streams (orsimultaneous data streams) is present or not.

FIG. 16 is a capability packet including duplex data stream informationaccording to an example.

Referring to FIG. 16 , the capability packet may include at least one ofa power class field, a maximum negotiable guaranteed power field, areserved field, a potential power field, an AI field regarding whetheran authentication initiator function is supported, an AR field regardingwhether an authentication responder function is supported, an OB fieldindicating whether outband communication is supported, a duplex datastream (DS) field, a WPID field, and an NRS field.

Referring back to FIG. 14 , an operation of exchanging, by the wirelesspower transmission apparatus and the wireless power reception apparatus,data streams may be any one of (A) or (B). According to the presentembodiment, one side receives duplex data stream information of theother side, checks whether the other side supports simultaneous datastreams, opens only one data stream if the other side does not supportthe simultaneous data streams, and opens a new data stream when thetransmission of the data stream is terminated.

First, (A) includes an operation of transmitting, by one side, a datastream to the other side. For example, the wireless power receptionapparatus may transmit a data stream to the wireless power transmissionapparatus (S1410), or the wireless power transmission apparatus maytransmit a data stream to the wireless power reception apparatus.

(A) is a case where at least one of the wireless power transmissionapparatus and the wireless power reception apparatus supports a singledata stream.

If both duplex data stream information of the wireless powertransmission apparatus and duplex data stream information of thewireless power reception apparatus indicate that the wireless powertransmission apparatus and the wireless power reception apparatussupport a single data stream or if duplex data stream information of thewireless power transmission apparatus indicates that the wireless powertransmission apparatus supports a single data stream and duplex datastream information of the wireless power reception apparatus indicatesthat the wireless power reception apparatus supports simultaneous datastreams or if duplex data stream information of the wireless powertransmission apparatus indicates that the wireless power transmissionapparatus supports simultaneous data streams and duplex data streaminformation of the wireless power reception apparatus indicates that thewireless power reception apparatus supports a single data stream, oneside opens a single (outgoing or incoming) data stream at a time withrespect to the other side, and opens a new (outgoing or incoming) datastream when the transmission of the single data stream is terminated.

(B) is a case where both the wireless power transmission apparatus andthe wireless power reception apparatus support simultaneous datastreams. In this case, one side opens an (outgoing or incoming) datastream with respect to the other side (S1415), and may open a new(outgoing or incoming) data stream before the transmission of the singledata stream is terminated (S1420).

The wireless power transmission apparatus in the embodiment of FIG. 14corresponds to the wireless power transmission apparatus or the wirelesspower transmitter or the power transmission unit disclosed in FIGS. 1 to11 . Accordingly, an operation of the wireless power transmissionapparatus in the present embodiment is implemented by one or acombination of two or more of the elements of the wireless powertransmission apparatus in FIGS. 1 to 11 . For example, an operation oftransmitting wireless power in the present embodiment may be performedby the power conversion circuit 110. Furthermore, in the presentembodiment, the operation of receiving the configuration packet, theoperation of generating and transmitting the capability packet, theoperation of opening, transmitting or receiving the data stream, etc.may be performed by the communication/control circuit 120.

Furthermore, the wireless power reception apparatus in the embodiment ofFIG. 14 corresponds to the wireless power reception apparatus or thewireless power receiver or the power reception unit disclosed in FIGS. 1to 11 . Accordingly, an operation of the wireless power receptionapparatus in the present embodiment is implemented by one or acombination of two or more of the elements of the wireless powerreception apparatus in FIGS. 1 to 11 . For example, an operation ofreceiving wireless power in the present embodiment may be performed bythe power pickup circuit 210. Furthermore, in the present embodiment,the operation of generating and transmitting the configuration packet,the operation of receiving the capability packet, the operation ofopening, transmitting or receiving the data stream, etc. may beperformed by the communication/control circuit 220.

Synchronization of Timing at which Power Loss is Calculated

FIG. 17 illustrates timing at which a wireless power reception apparatuscalculates received power according to an example.

Referring to FIG. 17 , the wireless power reception apparatus transmitsa received power (RP or RP8) packet, indicative of power received fromthe wireless power transmission apparatus, at a transmission period(T_received) interval of the received power packet. In this case, thereceived power packet is generated based on received power calculatedduring a window (t_window) from timing before a next received powerperiod is reached. That is, the wireless power reception apparatuscalculates power received from the wireless power transmission apparatusduring the window (t_window), generates the received power packet basedon a corresponding value, and transmits the generated received powerpacket to the wireless power transmission apparatus at timing (or timingat which a next received power period is reached) after an offset(t_offset) from timing at which the window (t_window) is ended. In thiscase, the window (t_window) may be defined as a silent period in whichinband communication does not occur between the wireless powertransmission apparatus and the wireless power reception apparatus.

Meanwhile, the wireless power transmission apparatus calculates orestimates power (Pt) transmitted to the wireless power receptionapparatus during the window (t_window) in which the wireless powerreception apparatus calculates the received power. Furthermore, thewireless power transmission apparatus calculates a power loss based on adifference between received power (Pr) and the transmission power (Pt)based on the received power packet, and performs foreign objectdetection (FOD) based on the power loss.

FIG. 18 illustrates timing at which a wireless power transmissionapparatus calculates transmission power according to an example.

Referring to FIG. 18 , the wireless power transmission apparatus cannotbe accurately aware of the start timing of a window (t_window) at whichthe wireless power reception apparatus calculates received power. Thereason for this is that synchronization related to the start timing ofthe window is not performed between the wireless power transmissionapparatus and the wireless power reception apparatus. As describedabove, if timing at which the wireless power transmission apparatuscalculates transmission power and timing at which the wireless powerreception apparatus calculates received power are not the same, there isa problem in that it is difficult to calculate an accurate power loss.Accordingly, the wireless power transmission apparatus continues tocalculate transmission power while sliding the window (t_window) at agiven interval (t_slide). Furthermore, the wireless power transmissionapparatus uses transmission power (Pt), calculated at timing earlierthan timing at which a received power packet (RP or RP8) is receivedfrom the wireless power reception apparatus by an offset (t_offset), tocalculate a power loss.

However, since the transmission period (t_received) of a received powerpacket is not fixed to a maximum 4050 ms (upon charging of 5 W or lessthan 5 W) or 2050 ms (upon charging of 5 W or more) value and isvariable, the wireless power transmission apparatus cannot be previouslyaware of timing at which the received power packet is received, andcannot be also previously aware of the window (t_window) section. Forexample, if the transmission period (t_received) of the received powerpacket varies, the wireless power transmission apparatus cannot be awareof the window (t_window) section in which the wireless power receptionapparatus calculates received power. This makes more difficult thematching of timing at which the wireless power transmission apparatuscalculates transmission power and timing at which the wireless powerreception apparatus calculates received power.

Furthermore, the wireless power transmission apparatus has to havecalculated transmission power every given interval in a sliding manner.This results in the waste of processing resources of the wireless powertransmission apparatus.

Accordingly, there is a need for a method of synchronizing pieces oftiming at which a power loss is calculated between the wireless powertransmission apparatus and reception apparatus. Hereinafter, disclosedis a method of synchronizing pieces of timing at which a power loss iscalculated between the wireless power transmission apparatus andreception apparatus.

FIG. 19 illustrates a method of operating a timing packet according toan example.

Referring to FIG. 19 , before transmitting a received power packet, thewireless power reception apparatus transmits, to the wireless powertransmission apparatus, a timing packet 1900 indicative of the start ofa window (t_window). The timing packet 1900 is a packet that notifiesthe wireless power transmission apparatus of the start of the window(t_window), and matches a section in which the wireless power receptionapparatus calculates received power and a section in which the wirelesspower transmission apparatus calculates transmission power. That is, thewireless power transmission apparatus and the wireless power receptionapparatus may perform power calculation during the same window(t_window) section using the timing packet 1900 as a starting point.

The timing packet 1900 may be called timing for an RP packet (TRPpacket). The timing packet 1900 may be configured with only headerinformation without a separate payload or data. That is, thesynchronization of power estimation timing may be achieved by the timingpacket 1900 having a minimum size. In this case, a value of a header maybe 0x00, for example.

An example of a relation between the timing packet 1900 and the starttiming of the window (t_window) may be the start timing of the window(t_window) at timing at which a predetermined given time(t_predetermined) has elapsed from timing at which the timing packet1900 was transmitted. In this case, the wireless power transmissionapparatus calculates or estimates transmission power during the window(t_window) at timing at which the predetermined given time(t_predetermined) has elapsed from the timing at which the timing packet1900 was received. Furthermore, the wireless power reception apparatuscalculates received power during the window (t_window) at timing atwhich the predetermined given time (t_predetermined) has elapsed fromthe timing at which the timing packet 1900 was transmitted.

Another example of a relation between the timing packet 1900 and thestart timing of the window (t_window) may be the start timing of thewindow (t_window) at timing at which the timing packet 1900 wastransmitted. In this case, the wireless power transmission apparatuscalculates or estimates transmission power during the window (t_window)from timing at which the timing packet 1900 was received. Furthermore,the wireless power reception apparatus calculates received power duringthe window (t_window) from timing at which the timing packet 1900 wastransmitted.

FIG. 20 illustrates a timing packet according to an example.

Referring to FIG. 20 , the timing packet may be defined as 8 bits, forexample, and a header to identify the timing packet may be defined as0x00, for example.

FIG. 21 illustrates a timing packet according to another example.

Referring to FIG. 21 , the timing packet is 8 bits, for example, and mayinclude a window size field and a window offset field. The window sizefield is 5 bits, for example, and a value thereof may define the size ofthe window (t_window) in unit of 4 ms. The window offset field is 3bits, for example, and a value thereof may define the size of a windowoffset (t_offset) in unit of 4 ms.

The window size field and the window offset field included in the timingpacket are used to adjust a default window (t_window) and a defaultwindow offset (t_offset). In this case, the default window and thedefault window offset are values included in a configuration packet. Thetiming packet of FIG. 21 may be identified by a header defined as 0x00,for example.

The wireless power transmission apparatus in the embodiment of FIGS. 19to 21 corresponds to the wireless power transmission apparatus or thewireless power transmitter or the power transmission unit disclosed inFIGS. 1 to 11 . Accordingly, an operation of the wireless powertransmission apparatus in the present embodiment is implemented by oneor a combination of two or more of the elements of the wireless powertransmission apparatus in FIGS. 1 to 11 . For example, the operation oftransmitting wireless power to the wireless power reception apparatusbased on magnetic coupling in the present embodiment may be performed bythe power conversion circuit 110. Furthermore, in the presentembodiment, the operation of receiving a timing packet, the operation ofcalculating or estimating transmitted power during a predeterminedwindow based on a timing packet, the operation of receiving a receivedpower packet, the operation of calculating a power loss based ontransmission power and received power, an operation of performingforeign object detection (FOD) based on a power loss may be performed bythe communication/control circuit 120.

Furthermore, the wireless power reception apparatus in the embodiment ofFIGS. 19 to 21 corresponds to the wireless power reception apparatus orthe wireless power receiver or the power reception unit disclosed inFIGS. 1 to 11 . Accordingly, an operation of the wireless powerreception apparatus in the present embodiment is implemented by one or acombination of two or more of the elements of the wireless powerreception apparatus in FIGS. 1 to 11 . For example, in the presentembodiment, the operation of receiving wireless power from the wirelesspower transmission apparatus based on magnetic coupling may be performedby the power pickup circuit 210. Furthermore, in the present embodiment,the operation of generating and transmitting a timing packet, theoperation of calculating received power, the operation of transmitting areceived power packet may be performed by the communication/controlcircuit 220.

Since the wireless power transmitting method and apparatus or thewireless power receiver and method according to an embodiment of thepresent disclosure do not necessarily include all the elements oroperations, the wireless power transmitter and method and the wirelesspower transmitter and method may be performed with the above-mentionedcomponents or some or all of the operations. Also, embodiments of theabove-described wireless power transmitter and method, or receivingapparatus and method may be performed in combination with each other.Also, each element or operation described above is necessarily performedin the order as described, and an operation described later may beperformed prior to an operation described earlier.

The description above is merely illustrating the technical spirit of thepresent disclosure, and various changes and modifications may be made bythose skilled in the art without departing from the essentialcharacteristics of the present disclosure. Therefore, the embodiments ofthe present disclosure described above may be implemented separately orin combination with each other.

Therefore, the embodiments disclosed in the present disclosure areintended to illustrate rather than limit the scope of the presentdisclosure, and the scope of the technical spirit of the presentdisclosure is not limited by these embodiments. The scope of the presentdisclosure should be construed by claims below, and all technicalspirits within a range equivalent to claims should be construed as beingincluded in the right scope of the present disclosure.

What is claimed is:
 1. A method for receiving a wireless power from awireless power transmitter, the method performed by a wireless powerreceiver and comprising: transmitting, to the wireless powertransmitter, a configuration packet comprising first information whichis composed of 1 bit, wherein the first information related to thewireless power receiver informs whether simultaneous incoming andoutgoing data stream are supported or not supported; receiving, from thewireless power transmitter, a capability packet comprising secondinformation which is composed of 1 bit, wherein the second informationrelated to the wireless power transmitter informs whether simultaneousincoming and outgoing data stream are supported or not supported;transmitting, to the wireless power transmitter, a first data streamthat includes: (i) an initial auxiliary data control (ADC) data packetopening the first data stream, (ii) a sequence of auxiliary datatransport (ADT) data packets including a first actual message, and (iii)a final ADC data packet closing the first data stream; and receiving,from the wireless power transmitter, a second data stream that includes:(i) an initial ADC data packet opening the second data stream, (ii) asequence of ADT data packets including a second actual message, and(iii) a final ADC data packet closing the second data stream, whereinthe wireless power receiver transmits the first data stream andsimultaneously receives the second data stream, based on the firstinformation and the second information, wherein the wireless powerreceiver transmits a first ADT data packet to the wireless powertransmitter, wherein based on the wireless power receiver receiving anacknowledge (ACK) in response to the first ADT data packet, the wirelesspower receiver transmits a second ADT data packet to the wireless powertransmitter, wherein, based on the second ADT data packet beingtransmitted, an ADT header is toggled from an even-number to anodd-number, wherein the toggled ADT header is transmitted with thesecond ADT data packet, and wherein, between transmitting the initialADC data packet related to the first data stream and transmitting thefinal ADC data packet related to the first data stream, the wirelesspower receiver transmits at least one control error packet related tocontrol information for a wireless charging to the wireless powertransmitter.
 2. The method of claim 1, wherein based on at least one ofthe first information and the second information not informingsimultaneous support, the wireless power receiver opens any one of thefirst data stream to the wireless power transmitter or the second datastream from the wireless power transmitter.
 3. The method of claim 1,wherein the wireless power receiver transmits, to the wireless powertransmitter, a timing packet informing a start of a window (t_window)providing a time interval in which the received wireless power iscalculated.
 4. A method for transferring a wireless power to a wirelesspower receiver, the method performed by a wireless power transmitter andcomprising: receiving, from the wireless power receiver, a configurationpacket comprising first information which is composed of 1 bit, whereinthe first information related to the wireless power receiver informswhether simultaneous incoming and outgoing data stream are supported ornot supported; transmitting, to the wireless power receiver, acapability packet comprising second information which is composed of 1bit, wherein the second information related to the wireless powertransmitter informs whether simultaneous incoming and outgoing datastream are supported or not supported; transmitting, to the wirelesspower receiver, a first data stream that includes: (i) an initialauxiliary data control (ADC) data packet opening the first data stream,(ii) a sequence of auxiliary data transport (ADT) data packets includinga first actual message, and (iii) a final ADC data packet closing thefirst data stream; and receiving, from the wireless power receiver, asecond data stream that includes: (i) an initial ADC data packet openingthe second data stream, (ii) a sequence of ADT data packets including asecond actual message, and (iii) a final ADC data packet closing thesecond data stream, wherein the wireless power transmitter transmits thefirst data stream and simultaneously receives the second data stream,based on the first information and the second information, wherein thewireless power transmitter receives a first ADT data packet from thewireless power receiver, wherein based on the wireless power transmittertransmitting an acknowledge (ACK) in response to the first ADT datapacket, the wireless power transmitter receives a second ADT data packetfrom the wireless power receiver, wherein, based on the second ADT datapacket being received, an ADT header is toggled from an even-number toan odd-number, wherein the toggled ADT header is received with thesecond ADT data packet, and wherein, between transmitting the initialADC data packet related to the first data stream and transmitting thefinal ADC data packet related to the first data stream, the wirelesspower transmitter receives at least one control error packet related tocontrol information for a wireless charging from the wireless powerreceiver.
 5. The method of claim 4, wherein based on at least one of thefirst information and the second information not informing simultaneoussupport, the wireless power transmitter opens any one of the first datastream to the wireless power transmitter or the second data stream fromthe wireless power transmitter.
 6. The method of claim 4, wherein thewireless power transmitter receives, from the wireless power receiver, atiming packet informing a start of a window (t_window) providing a timeinterval in which the transmitted wireless power is calculated.